Conduit headgear connector for patient interface

ABSTRACT

A patient interface may include: a plenum chamber at least partly defining a patient interface chamber, a seal-forming structure constructed and arranged to form a seal with a region of the patient&#39;s face, at least one conduit, at least one conduit connector configured to pneumatically connect the at least one conduit to the plenum chamber to provide a flow of air at a therapeutic pressure to the patient interface chamber for breathing by the patient, and a positioning and stabilising structure to provide a force to hold the seal-forming structure on the patient&#39;s head, the positioning and stabilising structure comprising at least one tie, wherein the at least one conduit connector includes an anti-asphyxia valve configured to allow the patient to breath from ambient through their mouth in the absence of a flow of pressurised air.

1 CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the U.S. national phase of International ApplicationNo. PCT/AU2018/051382 filed Dec. 21, 2018, which designated the U.S. andclaims the benefit of U.S. Provisional Application No. 62/609,909, filedDec. 22, 2017, the entire contents of each of which are incorporatedherein by reference.

A portion of the disclosure of this patent document contains materialwhich is subject to copyright protection. The copyright owner has noobjection to the facsimile reproduction by anyone of the patent documentor the patent disclosure, as it appears in Patent Office patent files orrecords, but otherwise reserves all copyright rights whatsoever.

2 BACKGROUND OF THE TECHNOLOGY 2.1 Field of the Technology

The present technology relates to one or more of the screening,diagnosis, monitoring, treatment, prevention and amelioration ofrespiratory-related disorders. The present technology also relates tomedical devices or apparatus, and their use.

2.2 Description of the Related Art

2.2.1 Human Respiratory System and its Disorders

The respiratory system of the body facilitates gas exchange. The noseand mouth form the entrance to the airways of a patient.

The airways include a series of branching tubes, which become narrower,shorter and more numerous as they penetrate deeper into the lung. Theprime function of the lung is gas exchange, allowing oxygen to move fromthe inhaled air into the venous blood and carbon dioxide to move in theopposite direction. The trachea divides into right and left mainbronchi, which further divide eventually into terminal bronchioles. Thebronchi make up the conducting airways, and do not take part in gasexchange. Further divisions of the airways lead to the respiratorybronchioles, and eventually to the alveoli. The alveolated region of thelung is where the gas exchange takes place, and is referred to as therespiratory zone. See “Respiratory Physiology”, by John B. West,Lippincott Williams & Wilkins, 9th edition published 2012.

A range of respiratory disorders exist. Certain disorders may becharacterised by particular events, e.g. apneas, hypopneas, andhyperpneas.

Examples of respiratory disorders include Obstructive Sleep Apnea (OSA),Cheyne-Stokes Respiration (CSR), respiratory insufficiency, ObesityHyperventilation Syndrome (OHS), Chronic Obstructive Pulmonary Disease(COPD), Neuromuscular Disease (NMD) and Chest wall disorders.

Obstructive Sleep Apnea (OSA), a form of Sleep Disordered Breathing(SDB), is characterised by events including occlusion or obstruction ofthe upper air passage during sleep. It results from a combination of anabnormally small upper airway and the normal loss of muscle tone in theregion of the tongue, soft palate and posterior oropharyngeal wallduring sleep. The condition causes the affected patient to stopbreathing for periods typically of 30 to 120 seconds in duration,sometimes 200 to 300 times per night. It often causes excessive daytimesomnolence, and it may cause cardiovascular disease and brain damage.The syndrome is a common disorder, particularly in middle agedoverweight males, although a person affected may have no awareness ofthe problem. See U.S. Pat. No. 4,944,310 (Sullivan).

Cheyne-Stokes Respiration (CSR) is another form of sleep disorderedbreathing. CSR is a disorder of a patient's respiratory controller inwhich there are rhythmic alternating periods of waxing and waningventilation known as CSR cycles. CSR is characterised by repetitivede-oxygenation and re-oxygenation of the arterial blood. It is possiblethat CSR is harmful because of the repetitive hypoxia. In some patientsCSR is associated with repetitive arousal from sleep, which causessevere sleep disruption, increased sympathetic activity, and increasedafterload. See U.S. Pat. No. 6,532,959 (Berthon-Jones).

Respiratory failure is an umbrella term for respiratory disorders inwhich the lungs are unable to inspire sufficient oxygen or exhalesufficient CO₂ to meet the patient's needs. Respiratory failure mayencompass some or all of the following disorders.

A patient with respiratory insufficiency (a form of respiratory failure)may experience abnormal shortness of breath on exercise.

Obesity Hyperventilation Syndrome (OHS) is defined as the combination ofsevere obesity and awake chronic hypercapnia, in the absence of otherknown causes for hypoventilation. Symptoms include dyspnea, morningheadache and excessive daytime sleepiness.

Chronic Obstructive Pulmonary Disease (COPD) encompasses any of a groupof lower airway diseases that have certain characteristics in common.These include increased resistance to air movement, extended expiratoryphase of respiration, and loss of the normal elasticity of the lung.Examples of COPD are emphysema and chronic bronchitis. COPD is caused bychronic tobacco smoking (primary risk factor), occupational exposures,air pollution and genetic factors. Symptoms include: dyspnea onexertion, chronic cough and sputum production.

Neuromuscular Disease (NMD) is a broad term that encompasses manydiseases and ailments that impair the functioning of the muscles eitherdirectly via intrinsic muscle pathology, or indirectly via nervepathology. Some NMD patients are characterised by progressive muscularimpairment leading to loss of ambulation, being wheelchair-bound,swallowing difficulties, respiratory muscle weakness and, eventually,death from respiratory failure. Neuromuscular disorders can be dividedinto rapidly progressive and slowly progressive: (i) Rapidly progressivedisorders: Characterised by muscle impairment that worsens over monthsand results in death within a few years (e.g. Amyotrophic lateralsclerosis (ALS) and Duchenne muscular dystrophy (DMD) in teenagers);(ii) Variable or slowly progressive disorders: Characterised by muscleimpairment that worsens over years and only mildly reduces lifeexpectancy (e.g. Limb girdle, Facioscapulohumeral and Myotonic musculardystrophy). Symptoms of respiratory failure in NMD include: increasinggeneralised weakness, dysphagia, dyspnea on exertion and at rest,fatigue, sleepiness, morning headache, and difficulties withconcentration and mood changes.

Chest wall disorders are a group of thoracic deformities that result ininefficient coupling between the respiratory muscles and the thoraciccage. The disorders are usually characterised by a restrictive defectand share the potential of long term hypercapnic respiratory failure.Scoliosis and/or kyphoscoliosis may cause severe respiratory failure.Symptoms of respiratory failure include: dyspnea on exertion, peripheraloedema, orthopnea, repeated chest infections, morning headaches,fatigue, poor sleep quality and loss of appetite.

A range of therapies have been used to treat or ameliorate suchconditions. Furthermore, otherwise healthy individuals may takeadvantage of such therapies to prevent respiratory disorders fromarising. However, these have a number of shortcomings.

2.2.2 Therapy

Various therapies, such as Continuous Positive Airway Pressure (CPAP)therapy, Non-invasive ventilation (NW) and Invasive ventilation (IV)have been used to treat one or more of the above respiratory disorders.

Continuous Positive Airway Pressure (CPAP) therapy has been used totreat Obstructive Sleep Apnea (OSA). The mechanism of action is thatcontinuous positive airway pressure acts as a pneumatic splint and mayprevent upper airway occlusion, such as by pushing the soft palate andtongue forward and away from the posterior oropharyngeal wall. Treatmentof OSA by CPAP therapy may be voluntary, and hence patients may electnot to comply with therapy if they find devices used to provide suchtherapy one or more of: uncomfortable, difficult to use, expensive andaesthetically unappealing.

Non-invasive ventilation (NIV) provides ventilatory support to a patientthrough the upper airways to assist the patient breathing and/ormaintain adequate oxygen levels in the body by doing some or all of thework of breathing. The ventilatory support is provided via anon-invasive patient interface. NIV has been used to treat CSR andrespiratory failure, in forms such as OHS, COPD, NMD and Chest Walldisorders. In some forms, the comfort and effectiveness of thesetherapies may be improved.

Invasive ventilation (IV) provides ventilatory support to patients thatare no longer able to effectively breathe themselves and may be providedusing a tracheostomy tube. In some forms, the comfort and effectivenessof these therapies may be improved.

2.2.3 Treatment Systems

These therapies may be provided by a treatment system or device. Suchsystems and devices may also be used to screen, diagnose, or monitor acondition without treating it.

A treatment system may comprise a Respiratory Pressure Therapy Device(RPT device), an air circuit, a humidifier, a patient interface, anddata management.

Another form of treatment system is a mandibular repositioning device.

2.2.3.1 Patient Interface

A patient interface may be used to interface respiratory equipment toits wearer, for example by providing a flow of air to an entrance to theairways. The flow of air may be provided via a mask to the nose and/ormouth, a tube to the mouth or a tracheostomy tube to the trachea of apatient. Depending upon the therapy to be applied, the patient interfacemay form a seal, e.g., with a region of the patient's face, tofacilitate the delivery of gas at a pressure at sufficient variance withambient pressure to effect therapy, e.g., at a positive pressure ofabout 10 cmH₂O relative to ambient pressure. For other forms of therapy,such as the delivery of oxygen, the patient interface may not include aseal sufficient to facilitate delivery to the airways of a supply of gasat a positive pressure of about 10 cmH₂O.

Certain other mask systems may be functionally unsuitable for thepresent field. For example, purely ornamental masks may be unable tomaintain a suitable pressure. Mask systems used for underwater swimmingor diving may be configured to guard against ingress of water from anexternal higher pressure, but not to maintain air internally at a higherpressure than ambient.

Certain masks may be clinically unfavourable for the present technologye.g. if they block airflow via the nose and only allow it via the mouth.

Certain masks may be uncomfortable or impractical for the presenttechnology if they require a patient to insert a portion of a maskstructure in their mouth to create and maintain a seal via their lips.

Certain masks may be impractical for use while sleeping, e.g. forsleeping while lying on one's side in bed with a head on a pillow.

The design of a patient interface presents a number of challenges. Theface has a complex three-dimensional shape. The size and shape of nosesand heads varies considerably between individuals. Since the headincludes bone, cartilage and soft tissue, different regions of the facerespond differently to mechanical forces. The jaw or mandible may moverelative to other bones of the skull. The whole head may move during thecourse of a period of respiratory therapy.

As a consequence of these challenges, some masks suffer from being oneor more of obtrusive, aesthetically undesirable, costly, poorly fitting,difficult to use, and uncomfortable especially when worn for longperiods of time or when a patient is unfamiliar with a system. Wronglysized masks can give rise to reduced compliance, reduced comfort andpoorer patient outcomes. Masks designed solely for aviators, masksdesigned as part of personal protection equipment (e.g. filter masks),SCUBA masks, or for the administration of anaesthetics may be tolerablefor their original application, but nevertheless such masks may beundesirably uncomfortable to be worn for extended periods of time, e.g.,several hours. This discomfort may lead to a reduction in patientcompliance with therapy. This is even more so if the mask is to be wornduring sleep.

CPAP therapy is highly effective to treat certain respiratory disorders,provided patients comply with therapy. If a mask is uncomfortable, ordifficult to use a patient may not comply with therapy. Since it isoften recommended that a patient regularly wash their mask, if a mask isdifficult to clean (e.g., difficult to assemble or disassemble),patients may not clean their mask and this may impact on patientcompliance.

While a mask for other applications (e.g. aviators) may not be suitablefor use in treating sleep disordered breathing, a mask designed for usein treating sleep disordered breathing may be suitable for otherapplications.

For these reasons, patient interfaces for delivery of CPAP during sleepform a distinct field.

2.2.3.1.1 Seal-Forming Structure

Patient interfaces may include a seal-forming structure. Since it is indirect contact with the patient's face, the shape and configuration ofthe seal-forming structure can have a direct impact the effectivenessand comfort of the patient interface.

A patient interface may be partly characterised according to the designintent of where the seal-forming structure is to engage with the face inuse. In one form of patient interface, a seal-forming structure maycomprise a first sub-portion to form a seal around the left naris and asecond sub-portion to form a seal around the right naris. In one form ofpatient interface, a seal-forming structure may comprise a singleelement that surrounds both nares in use. Such single element may bedesigned to for example overlay an upper lip region and a nasal bridgeregion of a face. In one form of patient interface a seal-formingstructure may comprise an element that surrounds a mouth region in use,e.g. by forming a seal on a lower lip region of a face. In one form ofpatient interface, a seal-forming structure may comprise a singleelement that surrounds both nares and a mouth region in use. Thesedifferent types of patient interfaces may be known by a variety of namesby their manufacturer including nasal masks, full-face masks, nasalpillows, nasal puffs and oro-nasal masks.

A seal-forming structure that may be effective in one region of apatient's face may be inappropriate in another region, e.g. because ofthe different shape, structure, variability and sensitivity regions ofthe patient's face. For example, a seal on swimming goggles thatoverlays a patient's forehead may not be appropriate to use on apatient's nose.

Certain seal-forming structures may be designed for mass manufacturesuch that one design fit and be comfortable and effective for a widerange of different face shapes and sizes. To the extent to which thereis a mismatch between the shape of the patient's face, and theseal-forming structure of the mass-manufactured patient interface, oneor both must adapt in order for a seal to form.

One type of seal-forming structure extends around the periphery of thepatient interface, and is intended to seal against the patient's facewhen force is applied to the patient interface with the seal-formingstructure in confronting engagement with the patient's face. Theseal-forming structure may include an air or fluid filled cushion, or amoulded or formed surface of a resilient seal element made of anelastomer such as a rubber. With this type of seal-forming structure, ifthe fit is not adequate, there will be gaps between the seal-formingstructure and the face, and additional force will be required to forcethe patient interface against the face in order to achieve a seal.

Another type of seal-forming structure incorporates a flap seal of thinmaterial positioned about the periphery of the mask so as to provide aself-sealing action against the face of the patient when positivepressure is applied within the mask. Like the previous style of sealforming portion, if the match between the face and the mask is not good,additional force may be required to achieve a seal, or the mask mayleak. Furthermore, if the shape of the seal-forming structure does notmatch that of the patient, it may crease or buckle in use, giving riseto leaks.

Another type of seal-forming structure may comprise a friction-fitelement, e.g. for insertion into a naris, however some patients findthese uncomfortable.

Another form of seal-forming structure may use adhesive to achieve aseal. Some patients may find it inconvenient to constantly apply andremove an adhesive to their face.

A range of patient interface seal-forming structure technologies aredisclosed in the following patent applications, assigned to ResMedLimited: WO 1998/004310; WO 2006/074513; WO 2010/135785.

One form of nasal pillow is found in the Adam Circuit manufactured byPuritan Bennett. Another nasal pillow, or nasal puff is the subject ofU.S. Pat. No. 4,782,832 (Trimble et al.), assigned to Puritan-BennettCorporation.

ResMed Limited has manufactured the following products that incorporatenasal pillows: SWIFT™ nasal pillows mask, SWIFT™ II nasal pillows mask,SWIFT™ LT nasal pillows mask, SWIFT™ FX nasal pillows mask and MIRAGELIBERTY™ full-face mask. The following patent applications, assigned toResMed Limited, describe examples of nasal pillows masks: InternationalPatent Application WO2004/073778 (describing amongst other thingsaspects of the ResMed Limited SWIFT™ nasal pillows), US PatentApplication 2009/0044808 (describing amongst other things aspects of theResMed Limited SWIFT™ LT nasal pillows); International PatentApplications WO 2005/063328 and WO 2006/130903 (describing amongst otherthings aspects of the ResMed Limited MIRAGE LIBERTY™ full-face mask);International Patent Application WO 2009/052560 (describing amongstother things aspects of the ResMed Limited SWIFT™ FX nasal pillows).

2.2.3.1.2 Positioning and Stabilising

A seal-forming structure of a patient interface used for positive airpressure therapy is subject to the corresponding force of the airpressure to disrupt a seal. Thus a variety of techniques have been usedto position the seal-forming structure, and to maintain it in sealingrelation with the appropriate portion of the face.

One technique is the use of adhesives. See for example US PatentApplication Publication No. US 2010/0000534. However, the use ofadhesives may be uncomfortable for some.

Another technique is the use of one or more straps and/or stabilisingharnesses. Many such harnesses suffer from being one or more ofill-fitting, bulky, uncomfortable and awkward to use.

2.2.3.2 Respiratory Pressure Therapy (RPT) Device

A respiratory pressure therapy (RPT) device may be used individually oras part of a system to implement one or more of a number of therapiesdescribed above, such as by operating the device to generate a flow ofair for delivery to an interface to the airways. The flow of air may bepressurised. Examples of RPT devices include a CPAP device and aventilator.

Air pressure generators are known in a range of applications, e.g.industrial-scale ventilation systems. However, air pressure generatorsfor medical applications have particular requirements not fulfilled bymore generalised air pressure generators, such as the reliability, sizeand weight requirements of medical devices. In addition, even devicesdesigned for medical treatment may suffer from shortcomings, pertainingto one or more of: comfort, noise, ease of use, efficacy, size, weight,manufacturability, cost, and reliability.

An example of the special requirements of certain RPT devices isacoustic noise.

Table of noise output levels of prior RPT devices (one specimen only,measured using test method specified in ISO 3744 in CPAP mode at 10cmH₂O).

A-weighted sound pressure level Year RPT Device name dB(A) (approx.)C-Series Tango ™ 31.9 2007 C-Series Tango ™ with 33.1 2007 Humidifier S8Escape ™ II 30.5 2005 S8 Escape ™ II with H4i ™ 31.1 2005 Humidifier S9AutoSet ™ 26.5 2010 S9 AutoSet ™ with H5i 28.6 2010 Humidifier

One known RPT device used for treating sleep disordered breathing is theS9 Sleep Therapy System, manufactured by ResMed Limited. Another exampleof an RPT device is a ventilator. Ventilators such as the ResMedStellar™ Series of Adult and Paediatric Ventilators may provide supportfor invasive and non-invasive non-dependent ventilation for a range ofpatients for treating a number of conditions such as but not limited toNMD, OHS and COPD.

The ResMed Elisée™ 150 ventilator and ResMed VS III™ ventilator mayprovide support for invasive and non-invasive dependent ventilationsuitable for adult or paediatric patients for treating a number ofconditions. These ventilators provide volumetric and barometricventilation modes with a single or double limb circuit. RPT devicestypically comprise a pressure generator, such as a motor-driven bloweror a compressed gas reservoir, and are configured to supply a flow ofair to the airway of a patient. In some cases, the flow of air may besupplied to the airway of the patient at positive pressure. The outletof the RPT device is connected via an air circuit to a patient interfacesuch as those described above.

The designer of a device may be presented with an infinite number ofchoices to make. Design criteria often conflict, meaning that certaindesign choices are far from routine or inevitable. Furthermore, thecomfort and efficacy of certain aspects may be highly sensitive tosmall, subtle changes in one or more parameters.

2.2.3.3 Humidifier

Delivery of a flow of air without humidification may cause drying ofairways. The use of a humidifier with an RPT device and the patientinterface produces humidified gas that minimizes drying of the nasalmucosa and increases patient airway comfort. In addition in coolerclimates, warm air applied generally to the face area in and about thepatient interface is more comfortable than cold air.

A range of artificial humidification devices and systems are known,however they may not fulfil the specialised requirements of a medicalhumidifier.

Medical humidifiers are used to increase humidity and/or temperature ofthe flow of air in relation to ambient air when required, typicallywhere the patient may be asleep or resting (e.g. at a hospital). Amedical humidifier for bedside placement may be small. A medicalhumidifier may be configured to only humidify and/or heat the flow ofair delivered to the patient without humidifying and/or heating thepatient's surroundings. Room-based systems (e.g. a sauna, an airconditioner, or an evaporative cooler), for example, may also humidifyair that is breathed in by the patient, however those systems would alsohumidify and/or heat the entire room, which may cause discomfort to theoccupants. Furthermore medical humidifiers may have more stringentsafety constraints than industrial humidifiers

While a number of medical humidifiers are known, they can suffer fromone or more shortcomings. Some medical humidifiers may provideinadequate humidification, some are difficult or inconvenient to use bypatients.

2.2.3.4 Data Management

There may be clinical reasons to obtain data to determine whether thepatient prescribed with respiratory therapy has been “compliant”, e.g.that the patient has used their RPT device according to one or more“compliance rules”. One example of a compliance rule for CPAP therapy isthat a patient, in order to be deemed compliant, is required to use theRPT device for at least four hours a night for at least 21 of 30consecutive days. In order to determine a patient's compliance, aprovider of the RPT device, such as a health care provider, may manuallyobtain data describing the patient's therapy using the RPT device,calculate the usage over a predetermined time period, and compare withthe compliance rule. Once the health care provider has determined thatthe patient has used their RPT device according to the compliance rule,the health care provider may notify a third party that the patient iscompliant.

There may be other aspects of a patient's therapy that would benefitfrom communication of therapy data to a third party or external system.

Existing processes to communicate and manage such data can be one ormore of costly, time-consuming, and error-prone.

2.2.3.5 Mandibular Repositioning

A mandibular repositioning device (MRD) or mandibular advancement device(MAD) is one of the treatment options for sleep apnea and snoring. It isan adjustable oral appliance available from a dentist or other supplierthat holds the lower jaw (mandible) in a forward position during sleep.The MRD is a removable device that a patient inserts into their mouthprior to going to sleep and removes following sleep. Thus, the MRD isnot designed to be worn all of the time. The MRD may be custom made orproduced in a standard form and includes a bite impression portiondesigned to allow fitting to a patient's teeth. This mechanicalprotrusion of the lower jaw expands the space behind the tongue, putstension on the pharyngeal walls to reduce collapse of the airway anddiminishes palate vibration.

In certain examples a mandibular advancement device may comprise anupper splint that is intended to engage with or fit over teeth on theupper jaw or maxilla and a lower splint that is intended to engage withor fit over teeth on the upper jaw or mandible. The upper and lowersplints are connected together laterally via a pair of connecting rods.The pair of connecting rods are fixed symmetrically on the upper splintand on the lower splint.

In such a design the length of the connecting rods is selected such thatwhen the MRD is placed in a patient's mouth the mandible is held in anadvanced position. The length of the connecting rods may be adjusted tochange the level of protrusion of the mandible. A dentist may determinea level of protrusion for the mandible that will determine the length ofthe connecting rods.

Some MRDs are structured to push the mandible forward relative to themaxilla while other MADs, such as the ResMed Narval CC™ MRD are designedto retain the mandible in a forward position. This device also reducesor minimises dental and temporo-mandibular joint (TMJ) side effects.Thus, it is configured to minimises or prevent any movement of one ormore of the teeth.

2.2.3.6 Vent Technologies

Some forms of treatment systems may include a vent to allow the washoutof exhaled carbon dioxide. The vent may allow a flow of gas from aninterior space of a patient interface, e.g., the plenum chamber, to anexterior of the patient interface, e.g., to ambient.

The vent may comprise an orifice and gas may flow through the orifice inuse of the mask. Many such vents are noisy. Others may become blocked inuse and thus provide insufficient washout. Some vents may be disruptiveof the sleep of a bed partner 1100 of the patient 1000, e.g. throughnoise or focussed airflow.

ResMed Limited has developed a number of improved mask venttechnologies. See International Patent Application Publication No. WO1998/034665; International Patent Application Publication No. WO2000/078381; U.S. Pat. No. 6,581,594; US Patent Application PublicationNo. US 2009/0050156; US Patent Application Publication No. 2009/0044808.

Table of noise of prior masks (ISO 17510-2:2007, 10 cmH₂O pressure at 1m)

A-weighted A-weighted sound power sound pressure Mask level dB(A) dB(A)Year Mask name type (uncertainty) (uncertainty) (approx.) Glue-on (*)nasal 50.9 42.9 1981 ResCare standard nasal 31.5 23.5 1993 (*) ResMedMirage ™ nasal 29.5 21.5 1998 (*) ResMed nasal 36 (3) 28 (3) 2000UltraMirage ™ ResMed Mirage nasal 32 (3) 24 (3) 2002 Activa ™ ResMedMirage nasal 30 (3) 22 (3) 2008 Micro ™ ResMed Mirage ™ nasal 29 (3) 22(3) 2008 SoftGel ResMed Mirage ™ nasal 26 (3) 18 (3) 2010 FX ResMedMirage nasal 37   29   2004 Swift ™ (*) pillows ResMed Mirage nasal 28(3) 20 (3) 2005 Swift ™ II pillows ResMed Mirage nasal 25 (3) 17 (3)2008 Swift ™ LT pillows ResMed AirFit P10 nasal 21 (3) 13 (3) 2014pillows (* one specimen only, measured using test method specified inISO 3744 in CPAP mode at 10 cmH₂O)

Sound pressure values of a variety of objects are listed below

A-weighted sound Object pressure dB(A) Notes Vacuum cleaner: 68 ISO 3744Nilfisk Walter Broadly Litter at 1 m distance Hog: B+ GradeConversational speech 60 1 m distance Average home 50 Quiet library 40Quiet bedroom at night 30 Background in TV studio 202.2.4 Screening, Diagnosis, and Monitoring Systems

Polysomnography (PSG) is a conventional system for diagnosis andmonitoring of cardio-pulmonary disorders, and typically involves expertclinical staff to apply the system. PSG typically involves the placementof 15 to 20 contact sensors on a patient in order to record variousbodily signals such as electroencephalography (EEG), electrocardiography(ECG), electrooculograpy (EOG), electromyography (EMG), etc. PSG forsleep disordered breathing has involved two nights of observation of apatient in a clinic, one night of pure diagnosis and a second night oftitration of treatment parameters by a clinician. PSG is thereforeexpensive and inconvenient. In particular it is unsuitable for homescreening/diagnosis/monitoring of sleep disordered breathing.

Screening and diagnosis generally describe the identification of acondition from its signs and symptoms. Screening typically gives atrue/false result indicating whether or not a patient's SDB is severeenough to warrant further investigation, while diagnosis may result inclinically actionable information. Screening and diagnosis tend to beone-off processes, whereas monitoring the progress of a condition cancontinue indefinitely. Some screening/diagnosis systems are suitableonly for screening/diagnosis, whereas some may also be used formonitoring.

Clinical experts may be able to screen, diagnose, or monitor patientsadequately based on visual observation of PSG signals. However, thereare circumstances where a clinical expert may not be available, or aclinical expert may not be affordable. Different clinical experts maydisagree on a patient's condition. In addition, a given clinical expertmay apply a different standard at different times.

3 BRIEF SUMMARY OF THE TECHNOLOGY

The present technology is directed towards providing medical devicesused in the screening, diagnosis, monitoring, amelioration, treatment,or prevention of respiratory disorders having one or more of improvedcomfort, cost, efficacy, ease of use and manufacturability.

A first aspect of the present technology relates to apparatus used inthe screening, diagnosis, monitoring, amelioration, treatment orprevention of a respiratory disorder.

Another aspect of the present technology relates to methods used in thescreening, diagnosis, monitoring, amelioration, treatment or preventionof a respiratory disorder.

An aspect of certain forms of the present technology is to providemethods and/or apparatus that improve the compliance of patients withrespiratory therapy.

An aspect of the present technology is directed to a patient interfacethat includes: a plenum chamber at least partly forming a patientinterface chamber that is pressurisable to a therapeutic pressure of atleast 6 cmH₂O above ambient air pressure, a seal-forming structureconstructed and arranged to form a seal with a region of the patient'sface surrounding an entrance to the patient's airways, a first conduitand a second conduit each being sized and structured to receive the flowof air at the therapeutic pressure for breathing by the patient, a firstconduit connector configured to pneumatically connect the first conduitto the plenum chamber to provide the flow of air at the therapeuticpressure to the patient interface chamber for breathing by the patientand a second conduit connector configured to pneumatically connect thesecond conduit to the plenum chamber to provide the flow of air at thetherapeutic pressure to the patient interface chamber for breathing bythe patient, a positioning and stabilising structure to provide a forceto hold the seal-forming structure in a therapeutically effectiveposition on the patient's head, the positioning and stabilisingstructure comprising at least one tie, and at least one anti-asphyxiavalve that is configured to allow the patient to breath from ambientthrough their mouth in the absence of a flow of pressurised air. In afurther example, at least one of the first conduit connector and thesecond conduit connector may include an anti-asphyxia valve.

An aspect of the present technology is directed to a patient interfacethat includes: a plenum chamber at least partly forming a patientinterface chamber that is pressurisable to a therapeutic pressure of atleast 6 cmH₂O above ambient air pressure, the plenum chamber including afirst plenum chamber hole and a second plenum chamber hole, the firstplenum chamber hole and the second plenum chamber hole each being sizedand structured to receive a flow of air at the therapeutic pressure forbreathing by a patient, a seal-forming structure constructed andarranged to form a seal with a region of the patient's face surroundingan entrance to the patient's airways, said seal-forming structure havingat least one hole therein such that the flow of air at the therapeuticpressure is delivered to at least an entrance to the patient's nares,the seal-forming structure constructed and arranged to maintain thetherapeutic pressure in the patient interface chamber throughout thepatient's respiratory cycle in use; a first conduit and a second conduiteach being sized and structured to receive the flow of air at thetherapeutic pressure for breathing by the patient; a first conduitconnector configured to pneumatically connect the first conduit to thefirst plenum chamber hole to provide the flow of air at the therapeuticpressure to the patient interface chamber for breathing by the patientand a second conduit connector configured to pneumatically connect thesecond conduit to the second plenum chamber hole to provide the flow ofair at the therapeutic pressure to the patient interface chamber forbreathing by the patient; and a positioning and stabilising structure toprovide a force to hold the seal-forming structure in a therapeuticallyeffective position on the patient's head, the positioning andstabilising structure comprising at least one tie, wherein the firstconduit connector and the second conduit connector each includes ananti-asphyxia valve that is configured to allow the patient to breathfrom ambient through their mouth in the absence of a flow of pressurisedair through the first plenum chamber hole and the second plenum chamberhole.

In examples, (a) the anti-asphyxia valve in each of the first conduitconnector and the second conduit connector may include an anti-asphyxiavalve hole, (b) each anti-asphyxia valve hole may be shaped anddimensioned to allow the patient to breathe therethrough if the otheranti-asphyxia valve hole is occluded, (c) the anti-asphyxia valve ineach of the first conduit connector and the second conduit connectorfurther may comprise an anti-asphyxia valve flap, (d) the anti-asphyxiavalve flap of each of the first conduit connector and the second conduitconnector may be configured to occlude the anti-asphyxia valve hole of acorresponding one of the first conduit connector and the second conduitconnector in a closed position such that the flow of air at thetherapeutic pressure traveling through a corresponding one of the firstconduit connector and the second conduit connector is directed to thepatient interface chamber and prevented from escaping to atmosphere viathe anti-asphyxia valve hole, (e) in an open position, the anti-asphyxiavalve flap of each of the first conduit connector and the second conduitconnector may be configured to allow the patient to breath from ambientthrough their mouth via the anti-asphyxia valve hole of a correspondingone of the first conduit connector and the second conduit connector inthe absence of a flow of pressurised air through the first plenumchamber hole and the second plenum chamber hole, (f) the anti-asphyxiavalve hole of each of the first conduit connector and the second conduitconnector may be divided by an anti-asphyxia valve hole divider thatprevents the corresponding anti-asphyxia valve flap from passing throughthe anti-asphyxia valve hole, (g) each anti-asphyxia valve flap maycomprise at least one vent hole to allow a portion of the flow of air atthe therapeutic pressure to escape to atmosphere therethrough, (h) theanti-asphyxia valve of each of the first conduit connector and thesecond conduit connector may comprise an anti-asphyxia valve flapconnector hole, and the anti-asphyxia valve flap of each of the firstconduit connector and the second conduit connector may comprise ananti-asphyxia valve flap connector to connect the anti-asphyxia valveflap to the anti-asphyxia valve flap connector hole the anti-asphyxiavalve of a corresponding one of the first conduit connector and thesecond conduit connector, (i) the anti-asphyxia valve of each of thefirst conduit connector and the second conduit connector may beconfigured to operate independently of the other, (j) each of the firstconduit connector and the second conduit connector may comprise at leastone conduit connector vent hole that is configured to allow a continuousflow of gases exhaled by the patient from an interior of the patientinterface chamber to ambient, the at least one conduit connector venthole being sized and shaped to maintain the therapeutic pressure in thepatient interface chamber in use, (k) each of the first conduitconnector and the second conduit connector may comprise a conduitconnector vent inlet that is configured to direct the continuous flow ofgases exhaled by the patient from the interior of the patient interfacechamber to the at least one conduit connector vent hole, (l) each of thefirst conduit connector and the second conduit connector may comprise aconduit connector vent outlet that is configured to direct thecontinuous flow of gases exhaled by the patient from the at least oneconduit connector vent hole to atmosphere, (m) each of the first conduitconnector and the second conduit connector may comprise a baffle toprevent the flow of air at the therapeutic pressure passing through eachof the first conduit connector and the second conduit connector frompassing directly to atmosphere via the at least one conduit connectorvent hole, (n) each of the first conduit connector and the secondconduit connector may comprise a diffuser cavity containing a diffusermaterial, (o) the diffuser cavity and the diffuser material may bepositioned downstream of the at least one conduit connector vent holerelative to the continuous flow of gases to diffuse the continuous flowof gases before escaping to atmosphere, (p) each of the first conduitconnector and the second conduit connector may comprise a diffuser coverthat encloses the diffuser material within the diffuser cavity, (q) thediffuser cover may be removable to allow removal and replacement of thediffuser material, (r) each of the first conduit connector and thesecond conduit connector may comprise a conduit connector vent outletthat is positioned such that at least a portion of the continuous flowof gases passes through the diffuser material before escaping toatmosphere via the conduit connector vent outlet, (s) each of the firstconduit connector and the second conduit connector may comprise aconduit connector spacer to maintain a gap between a portion of each ofthe first conduit connector and the second conduit connector and theplenum chamber to allow the continuous flow of gases to escape from eachof the first conduit connector and the second conduit connector toatmosphere, (t) the plenum chamber may comprise at least one plenumchamber vent hole, (u) the plenum chamber may comprise a plurality ofplenum chamber vent holes, (v) each of the first conduit connector andthe second conduit connector may comprise a conduit connection end thatis configured to be connected to a corresponding one of the firstconduit and the second conduit, (w) each of the first conduit connectorand the second conduit connector may comprise a conduit connector endthat defines a conduit connector inlet hole that is configured toreceive the flow of air at the therapeutic pressure from a correspondingone of the first conduit and the second conduit, (x) each of the firstconduit connector and the second conduit connector may comprise aconduit connector outlet that defines a conduit connector outlet holethat is configured to direct the flow of air at the therapeutic pressureinto the patient interface chamber, (y) each conduit connector end maybe oriented substantially orthogonally to a corresponding conduitconnector outlet, (z) the plenum chamber may comprise a connection rimat a corresponding one of the first plenum chamber hole and the secondplenum chamber hole, and each of the first conduit connector and thesecond conduit connector may comprise at least one conduit connectorattachment structure that is configured to connect to the connection rimat a corresponding one of the first plenum chamber hole and the secondplenum chamber hole, (aa) each of the first conduit connector and thesecond conduit connector may be removable from the plenum chamber, (bb)each of the first conduit connector and the second conduit connector maybe permanently connected to the plenum chamber, (cc) each of the firstconduit connector and the second conduit connector is configured toremain stationary when connected to the plenum chamber, (dd) the patientinterface may further comprise a seal between each of the first conduitconnector and the second conduit connector and a corresponding one ofthe first plenum chamber hole and the second plenum chamber hole, (ee)the seal may be formed on each of the first conduit connector and thesecond conduit connector, the seal being configured to engage the plenumchamber at a corresponding one of the first plenum chamber hole and thesecond plenum chamber hole, (ff) the seal may be permanently joined to acorresponding one of the first conduit connector and the second conduitconnector, (gg) the seal may be constructed of silicone, (hh) thepositioning and stabilising structure may comprise a pair of superiorties, each of the superior ties being constructed and arranged so thatat least a portion of the superior tie overlies a corresponding lateralregion of the patient's head superior to an otobasion superior of thepatient's head in use, and the positioning and stabilising structure maycomprises a pair of inferior ties, each of the inferior ties beingconstructed and arranged so that at least a portion of the inferior tieoverlies a corresponding lateral region of the patient's head inferiorto an otobasion inferior of the patient's head in use, (ii) each of thefirst conduit connector and the second conduit connector may comprise aninferior tie connector that is configured to be connected to acorresponding one of the inferior ties, (jj) a clip may releasablyconnect each of the inferior ties to a corresponding one of the inferiortie connectors, (kk) the clip may comprise a magnet, (ll) the patientinterface may further comprise a pair of inferior tie tabs eachconfigured to be connected to a corresponding one of the inferior ties,and each of the first conduit connector and the second conduit connectormay further comprise a flange configured to be connected a correspondingone of the inferior tie tabs, (mm) each of the flanges may furthercomprise a flange opening and a recess, each of the inferior tie tabsmay further comprise a tab connector configured to join each of theinferior tie tabs to a corresponding one of the flanges by passingthrough the corresponding flange opening and engaging the correspondingrecess, (nn) the patient interface may further comprise a clipconfigured to be connected to each of the inferior ties, each of theinferior tie tabs may further comprise a clip receiver configured to beremovably connected to a corresponding one of the clips to connect theinferior ties, (oo) each of the clips and each of the clip receivers maycomprise a magnet oriented and charged to facilitate a removableconnection, (pp) each of the clip receivers may comprise a notch andeach of the clips comprise a protrusion, each protrusion beingconfigured to engage a corresponding notch to limit rotation of the cliprelative to the corresponding clip receiver, (qq) each of the firstconduit connector and the second conduit connector may further comprisea first tab and a second tab to releasably connect the first conduitconnector and the second conduit connector to the plenum chamber at thefirst plenum chamber hole and the second plenum chamber hole,respectively, (rr) the first tab and the second tab may be configuredsuch that the first conduit connector and the second conduit connectorare only connectable to the plenum chamber by engaging the first tabwith the plenum chamber followed by engaging the second tab with theplenum chamber, (ss) the first tab and the second tab may be configuredsuch that the first conduit connector and the second conduit connectorare only disconnectable from the plenum chamber by disengaging thesecond tab from the plenum chamber followed by disengaging the first tabfrom the plenum chamber, (tt) the plenum chamber may further comprises aslot proximal to each of the first plenum chamber hole and the secondplenum chamber hole, the first tab of each of the first conduitconnector and the second conduit connector may be configured to engagethe slot associated with a corresponding one of the first plenum chamberhole and the second plenum chamber hole, and each of the first conduitconnector and the second conduit connector may be rotatable about thecorresponding slot when the first tab of each of the first conduitconnector and the second conduit connector is engaged with thecorresponding slot, (uu) the plenum chamber may further comprises adetent proximal to each of the first plenum chamber hole and the secondplenum chamber hole, and the second tab of each of the first conduitconnector and the second conduit connector may further comprise a catch,the catch being configured to engage the detent associated with acorresponding one of the first plenum chamber hole and the second plenumchamber hole with a snap-fit, (vv) the second tab of each of the firstconduit connector and the second conduit connector may be flexible, (ww)each of the first conduit connector and the second conduit connector mayfurther comprise a gap on each side of the corresponding second tab suchthat the second tab is cantilevered from each of the first conduitconnector and the second conduit connector (xx) the seal-formingstructure may comprise a nasal portion configured to seal around thepatient's nares and an oral portion configured to seal around thepatient's mouth, (yy) the seal-forming structure may comprise a nasalportion hole configured to provide pneumatic communication between thepatient's nares and the patient interface chamber, and the seal-formingstructure may comprise an oral portion hole configured to providepneumatic communication between the patient's mouth and the patientinterface chamber, (zz) the patient interface may comprise a connectionport housing, each of the first conduit and the second conduit inpneumatic communication with the connection port housing, and aconnection port connected to the connection port housing, the connectionport configured to be connected to an air circuit to receive the flow ofair at the therapeutic pressure, (aaa) the connection port may comprisean elbow, (bbb) the connection port may comprise at least one vent hole,(ccc) the connection port may be swivelably connected to the connectionport housing, and/or (ddd) the connection port and the connection porthousing may be configured to be positioned superior to the patient'shead in use.

Another aspect of the present technology is directed to a respiratorytherapy system that may comprise: the patient interface according to anyof the examples of the three preceding paragraphs; a respiratorypressure therapy device configured to generate the flow of air at thetherapeutic pressure; and an air circuit configured to direct the flowof air at the therapeutic pressure from the respiratory pressure therapydevice to the patient interface.

Another aspect of one form of the present technology is a patientinterface that is moulded or otherwise constructed with a perimetershape which is complementary to that of an intended wearer.

An aspect of one form of the present technology is a method ofmanufacturing apparatus.

An aspect of certain forms of the present technology is a medical devicethat is easy to use, e.g. by a person who does not have medicaltraining, by a person who has limited dexterity, vision or by a personwith limited experience in using this type of medical device.

An aspect of one form of the present technology is a portable RPT devicethat may be carried by a person, e.g., around the home of the person.

An aspect of one form of the present technology is a patient interfacethat may be washed in a home of a patient, e.g., in soapy water, withoutrequiring specialised cleaning equipment. An aspect of one form of thepresent technology is a humidifier tank that may be washed in a home ofa patient, e.g., in soapy water, without requiring specialised cleaningequipment.

The methods, systems, devices and apparatus described may be implementedso as to improve the functionality of a processor, such as a processorof a specific purpose computer, respiratory monitor and/or a respiratorytherapy apparatus. Moreover, the described methods, systems, devices andapparatus can provide improvements in the technological field ofautomated management, monitoring and/or treatment of respiratoryconditions, including, for example, sleep disordered breathing.

Of course, portions of the aspects may form sub-aspects of the presenttechnology. Also, various ones of the sub-aspects and/or aspects may becombined in various manners and also constitute additional aspects orsub-aspects of the present technology.

Other features of the technology will be apparent from consideration ofthe information contained in the following detailed description,abstract, drawings and claims.

4 BRIEF DESCRIPTION OF THE DRAWINGS

The present technology is illustrated by way of example, and not by wayof limitation, in the figures of the accompanying drawings, in whichlike reference numerals refer to similar elements including:

4.1 Treatment Systems

FIG. 1A shows a system including a patient 1000 wearing a patientinterface 3000, in the form of nasal pillows, receiving a supply of airat positive pressure from an RPT device 4000. Air from the RPT device4000 is humidified in a humidifier 5000, and passes along an air circuit4170 to the patient 1000. A bed partner 1100 is also shown. The patientis sleeping in a supine sleeping position.

FIG. 1B shows a system including a patient 1000 wearing a patientinterface 3000, in the form of a nasal mask, receiving a supply of airat positive pressure from an RPT device 4000. Air from the RPT device ishumidified in a humidifier 5000, and passes along an air circuit 4170 tothe patient 1000.

FIG. 1C shows a system including a patient 1000 wearing a patientinterface 3000, in the form of a full-face mask, receiving a supply ofair at positive pressure from an RPT device 4000. Air from the RPTdevice is humidified in a humidifier 5000, and passes along an aircircuit 4170 to the patient 1000. The patient is sleeping in a sidesleeping position.

4.2 Respiratory System and Facial Anatomy

FIG. 2A shows an overview of a human respiratory system including thenasal and oral cavities, the larynx, vocal folds, oesophagus, trachea,bronchus, lung, alveolar sacs, heart and diaphragm.

FIG. 2B shows a view of a human upper airway including the nasal cavity,nasal bone, lateral nasal cartilage, greater alar cartilage, nostril,lip superior, lip inferior, larynx, hard palate, soft palate,oropharynx, tongue, epiglottis, vocal folds, oesophagus and trachea.

FIG. 2C is a front view of a face with several features of surfaceanatomy identified including the lip superior, upper vermilion, lowervermilion, lip inferior, mouth width, endocanthion, a nasal ala,nasolabial sulcus and cheilion. Also indicated are the directionssuperior, inferior, radially inward and radially outward.

FIG. 2D is a side view of a head with several features of surfaceanatomy identified including glabella, sellion, pronasale, subnasale,lip superior, lip inferior, supramenton, nasal ridge, alar crest point,otobasion superior and otobasion inferior. Also indicated are thedirections superior & inferior, and anterior & posterior.

FIG. 2E is a further side view of a head. The approximate locations ofthe Frankfort horizontal and nasolabial angle are indicated. The coronalplane is also indicated.

FIG. 2F shows a base view of a nose with several features identifiedincluding naso-labial sulcus, lip inferior, upper Vermilion, naris,subnasale, columella, pronasale, the major axis of a naris and themidsagittal plane.

FIG. 2G shows a side view of the superficial features of a nose.

FIG. 2H shows subcutaneal structures of the nose, including lateralcartilage, septum cartilage, greater alar cartilage, lesser alarcartilage, sesamoid cartilage, nasal bone, epidermis, adipose tissue,frontal process of the maxilla and fibrofatty tissue.

FIG. 2I shows a medial dissection of a nose, approximately severalmillimeters from the midsagittal plane, amongst other things showing theseptum cartilage and medial crus of greater alar cartilage.

FIG. 2J shows a front view of the bones of a skull including thefrontal, nasal and zygomatic bones. Nasal concha are indicated, as arethe maxilla, and mandible.

FIG. 2K shows a lateral view of a skull with the outline of the surfaceof a head, as well as several muscles. The following bones are shown:frontal, sphenoid, nasal, zygomatic, maxilla, mandible, parietal,temporal and occipital. The mental protuberance is indicated. Thefollowing muscles are shown: digastricus, masseter, sternocleidomastoidand trapezius.

FIG. 2L shows an anterolateral view of a nose.

4.3 Patient Interface

FIG. 3A shows a patient interface in the form of a nasal mask inaccordance with one form of the present technology.

FIG. 3B shows a schematic of a cross-section through a structure at apoint. An outward normal at the point is indicated. The curvature at thepoint has a positive sign, and a relatively large magnitude whencompared to the magnitude of the curvature shown in FIG. 3C.

FIG. 3C shows a schematic of a cross-section through a structure at apoint. An outward normal at the point is indicated. The curvature at thepoint has a positive sign, and a relatively small magnitude whencompared to the magnitude of the curvature shown in FIG. 3B.

FIG. 3D shows a schematic of a cross-section through a structure at apoint. An outward normal at the point is indicated. The curvature at thepoint has a value of zero.

FIG. 3E shows a schematic of a cross-section through a structure at apoint. An outward normal at the point is indicated. The curvature at thepoint has a negative sign, and a relatively small magnitude whencompared to the magnitude of the curvature shown in FIG. 3F.

FIG. 3F shows a schematic of a cross-section through a structure at apoint. An outward normal at the point is indicated. The curvature at thepoint has a negative sign, and a relatively large magnitude whencompared to the magnitude of the curvature shown in FIG. 3E.

FIG. 3G shows a cushion for a mask that includes two pillows. Anexterior surface of the cushion is indicated. An edge of the surface isindicated. Dome and saddle regions are indicated.

FIG. 3H shows a cushion for a mask. An exterior surface of the cushionis indicated. An edge of the surface is indicated. A path on the surfacebetween points A and B is indicated. A straight line distance between Aand B is indicated. Two saddle regions and a dome region are indicated.

FIG. 3I shows the surface of a structure, with a one dimensional hole inthe surface. The illustrated plane curve forms the boundary of a onedimensional hole.

FIG. 3J shows a cross-section through the structure of FIG. 3I. Theillustrated surface bounds a two dimensional hole in the structure ofFIG. 3I.

FIG. 3K shows a perspective view of the structure of FIG. 3I, includingthe two dimensional hole and the one dimensional hole. Also shown is thesurface that bounds a two dimensional hole in the structure of FIG. 3I.

FIG. 3L shows a mask having an inflatable bladder as a cushion.

FIG. 3M shows a cross-section through the mask of FIG. 3L, and shows theinterior surface of the bladder. The interior surface bounds the twodimensional hole in the mask.

FIG. 3N shows a further cross-section through the mask of FIG. 3L. Theinterior surface is also indicated.

FIG. 3O illustrates a left-hand rule.

FIG. 3P illustrates a right-hand rule.

FIG. 3Q shows a left ear, including the left ear helix.

FIG. 3R shows a right ear, including the right ear helix.

FIG. 3S shows a right-hand helix.

FIG. 3T shows a view of a mask, including the sign of the torsion of thespace curve defined by the edge of the sealing membrane in differentregions of the mask.

FIG. 3U shows a view of a plenum chamber 3200 showing a sagittal planeand a mid-contact plane.

FIG. 3V shows a view of a posterior of the plenum chamber of FIG. 3U.The direction of the view is normal to the mid-contact plane. Thesagittal plane in FIG. 3V bisects the plenum chamber into left-hand andright-hand sides.

FIG. 3W shows a cross-section through the plenum chamber of FIG. 3V, thecross-section being taken at the sagittal plane shown in FIG. 3V. A‘mid-contact’ plane is shown. The mid-contact plane is perpendicular tothe sagittal plane. The orientation of the mid-contact plane correspondsto the orientation of a chord 3210 which lies on the sagittal plane andjust touches the cushion of the plenum chamber at two points on thesagittal plane: a superior point 3220 and an inferior point 3230.Depending on the geometry of the cushion in this region, the mid-contactplane may be a tangent at both the superior and inferior points.

FIG. 3X shows the plenum chamber 3200 of FIG. 3U in position for use ona face. The sagittal plane of the plenum chamber 3200 generallycoincides with the midsagittal plane of the face when the plenum chamberis in position for use. The mid-contact plane corresponds generally tothe ‘plane of the face’ when the plenum chamber is in position for use.In FIG. 3X the plenum chamber 3200 is that of a nasal mask, and thesuperior point 3220 sits approximately on the sellion, while theinferior point 3230 sits on the lip superior.

4.4 RPT Device

FIG. 4A shows an RPT device in accordance with one form of the presenttechnology.

FIG. 4B is a schematic diagram of the pneumatic path of an RPT device inaccordance with one form of the present technology. The directions ofupstream and downstream are indicated with reference to the blower andthe patient interface. The blower is defined to be upstream of thepatient interface and the patient interface is defined to be downstreamof the blower, regardless of the actual flow direction at any particularmoment. Items which are located within the pneumatic path between theblower and the patient interface are downstream of the blower andupstream of the patient interface.

FIG. 4C is a schematic diagram of the electrical components of an RPTdevice in accordance with one form of the present technology.

4.5 Humidifier

FIG. 5A shows an isometric view of a humidifier in accordance with oneform of the present technology.

FIG. 5B shows an isometric view of a humidifier in accordance with oneform of the present technology, showing a humidifier reservoir 5110removed from the humidifier reservoir dock 5130.

FIG. 5C shows a schematic of a humidifier in accordance with one form ofthe present technology.

4.6 Breathing Waveforms

FIG. 6 shows a model typical breath waveform of a person while sleeping.

4.7 Examples of the Present Technology

FIG. 7 depicts an anterior perspective view of a patient interfaceaccording to an example of the present technology.

FIG. 8 depicts a posterior perspective view of a patient interfaceaccording to an example of the present technology.

FIG. 9 depicts an inferior view of a patient interface according to anexample of the present technology.

FIG. 10 depicts an anterior view of a patient interface according to anexample of the present technology.

FIG. 11 depicts a posterior view of a patient interface according to anexample of the present technology.

FIG. 12 depicts a cross-sectional view of a patient interface accordingto an example of the present technology taken through line 12-12 of FIG.11.

FIG. 13 depicts a lateral view of a patient interface according to anexample of the present technology.

FIG. 14 depicts a cross-sectional view of a patient interface accordingto an example of the present technology taken through line 14, 15-14, 15of FIG. 13.

FIG. 15 depicts a cross-sectional view of a patient interface accordingto an example of the present technology taken through line 14, 15-14, 15of FIG. 13.

FIG. 16 depicts an anterior perspective view of a patient interfaceaccording to an example of the present technology.

FIG. 17 depicts a posterior perspective view of a patient interfaceaccording to an example of the present technology.

FIG. 18 depicts a superior view of a patient interface according to anexample of the present technology.

FIG. 19 depicts an anterior perspective view of a sub-assembly of apatient interface according to an example of the present technology.

FIG. 20 depicts an anterior view of a sub-assembly of a patientinterface according to an example of the present technology.

FIG. 21 depicts a posterior perspective view of a sub-assembly of apatient interface according to an example of the present technology.

FIG. 22 depicts a posterior view of a sub-assembly of a patientinterface according to an example of the present technology.

FIG. 23 depicts a cross-sectional view of a sub-assembly of a patientinterface according to an example of the present technology takenthrough line 23-23 of FIG. 22.

FIG. 24 depicts a lateral view of a sub-assembly of a patient interfaceaccording to an example of the present technology.

FIG. 25 depicts an anterior perspective view of a conduit connector fora patient interface according to an example of the present technology.

FIG. 26 depicts a posterior perspective view of a conduit connector fora patient interface according to an example of the present technology.

FIG. 27 depicts a lateral perspective view of a conduit connector for apatient interface according to an example of the present technology.

FIG. 28 depicts a superior view of a conduit connector for a patientinterface according to an example of the present technology.

FIG. 29 depicts a cross-sectional view of a conduit connector for apatient interface according to an example of the present technologytaken through line 29, 30-29, 30 of FIG. 28.

FIG. 30 depicts a cross-sectional view of a conduit connector for apatient interface according to an example of the present technologytaken through line 29, 30-29, 30 of FIG. 28.

FIG. 31 depicts an anterior perspective view of a conduit connector fora patient interface according to an example of the present technology.

FIG. 32 depicts an anterior perspective view of a patient interfaceaccording to an example of the present technology.

FIG. 33 depicts an anterior view of a patient interface according to anexample of the present technology.

FIG. 34 depicts an anterior perspective view of a patient interfaceaccording to an example of the present technology worn by a patient.

FIG. 35 depicts a lateral view of a patient interface according to anexample of the present technology worn by a patient.

FIG. 36 depicts an anterior perspective view of a patient interfaceaccording to an example of the present technology worn by a patient.

FIG. 37 depicts a superior perspective view of a connection port for apatient interface according to an example of the present technology.

FIG. 38 depicts an inferior perspective view of a connection port for apatient interface according to an example of the present technology.

FIG. 39 depicts an anterior perspective view of a patient interfaceaccording to an example of the present technology.

FIG. 40 depicts a posterior perspective view of a patient interfaceaccording to an example of the present technology.

FIG. 41 depicts an inferior view of a patient interface according to anexample of the present technology.

FIG. 42 depicts an anterior view of a patient interface according to anexample of the present technology.

FIG. 43 depicts a posterior view of a patient interface according to anexample of the present technology.

FIG. 44 depicts a cross-sectional view of a patient interface accordingto an example of the present technology taken through line 44-44 of FIG.43.

FIG. 45 depicts a lateral view of a patient interface according to anexample of the present technology.

FIG. 46 depicts a cross-sectional view of a patient interface accordingto an example of the present technology taken through line 46, 47-46, 47of FIG. 45.

FIG. 47 depicts a cross-sectional view of a patient interface accordingto an example of the present technology taken through line 46, 47-46, 47of FIG. 45.

FIG. 48 depicts an anterior perspective view of a patient interfaceaccording to an example of the present technology.

FIG. 49 depicts a posterior perspective view of a patient interfaceaccording to an example of the present technology.

FIG. 50 depicts a superior view of a patient interface according to anexample of the present technology.

FIG. 51 depicts an anterior perspective view of a sub-assembly of apatient interface according to an example of the present technology.

FIG. 52 depicts an anterior view of a sub-assembly of a patientinterface according to an example of the present technology.

FIG. 53 depicts a posterior perspective view of a sub-assembly of apatient interface according to an example of the present technology.

FIG. 54 depicts a posterior view of a sub-assembly of a patientinterface according to an example of the present technology.

FIG. 55 depicts a cross-sectional view of a sub-assembly of a patientinterface according to an example of the present technology takenthrough line 55-55 of FIG. 54.

FIG. 56 depicts a posterior perspective view of a conduit connector fora patient interface according to an example of the present technology.

FIG. 57 depicts an exploded posterior perspective view of a conduitconnector for a patient interface according to an example of the presenttechnology.

FIG. 58 depicts an exploded anterior perspective view of a conduitconnector for a patient interface according to an example of the presenttechnology.

FIG. 59 depicts a superior view of a conduit connector for a patientinterface according to an example of the present technology.

FIG. 60 depicts a cross-sectional view of a conduit connector for apatient interface according to an example of the present technologytaken through line 59, 60-59, 60 of FIG. 58.

FIG. 61 depicts a cross-sectional view of a conduit connector for apatient interface according to an example of the present technologytaken through line 59, 60-59, 60 of FIG. 58.

FIG. 62 depicts an anterior perspective view of a conduit connector fora patient interface according to an example of the present technology.

FIG. 63 depicts another cross-sectional view of a conduit connector fora patient interface joined to a conduit according to an example of thepresent technology.

FIG. 64 depicts an anterior view of a patient interface according to anexample of the present technology.

FIG. 65 depicts an anterior perspective view of a patient interfaceaccording to an example of the present technology.

FIG. 66 depicts a posterior view of a positioning and stabilisingstructure according to an example of the present technology.

FIG. 67 depicts a perspective view of a clip according to an example ofthe present technology.

FIG. 68 depicts a perspective view of a clip according to an example ofthe present technology.

5 DETAILED DESCRIPTION OF EXAMPLES OF THE TECHNOLOGY

Before the present technology is described in further detail, it is tobe understood that the technology is not limited to the particularexamples described herein, which may vary. It is also to be understoodthat the terminology used in this disclosure is for the purpose ofdescribing only the particular examples discussed herein, and is notintended to be limiting.

The following description is provided in relation to various exampleswhich may share one or more common characteristics and/or features. Itis to be understood that one or more features of any one example may becombinable with one or more features of another example or otherexamples. In addition, any single feature or combination of features inany of the examples may constitute a further example.

5.1 Therapy

In one form, the present technology comprises a method for treating arespiratory disorder comprising the step of applying positive pressureto the entrance of the airways of a patient 1000.

In certain examples of the present technology, a supply of air atpositive pressure is provided to the nasal passages of the patient viaone or both nares.

In certain examples of the present technology, mouth breathing islimited, restricted or prevented.

5.2 Treatment Systems

In one form, the present technology comprises an apparatus or device fortreating a respiratory disorder. The apparatus or device may comprise anRPT device 4000 for supplying pressurised air to the patient 1000 via anair circuit 4170 to a patient interface 3000.

5.3 Patient Interface

A non-invasive patient interface 3000 in accordance with one aspect ofthe present technology comprises the following functional aspects: aseal-forming structure 3100, a plenum chamber 3200, a positioning andstabilising structure 3300, a vent 3400, one form of connection port3600 for connection to air circuit 4170, and a forehead support 3700. Insome forms a functional aspect may be provided by one or more physicalcomponents. In some forms, one physical component may provide one ormore functional aspects. In use the seal-forming structure 3100 isarranged to surround an entrance to the airways of the patient so as tofacilitate the supply of air at positive pressure to the airways.

If a patient interface is unable to comfortably deliver a minimum levelof positive pressure to the airways, the patient interface may beunsuitable for respiratory pressure therapy.

The patient interface 3000 in accordance with one form of the presenttechnology is constructed and arranged to be able to provide a supply ofair at a positive pressure of at least 6 cmH₂O with respect to ambient.

The patient interface 3000 in accordance with one form of the presenttechnology is constructed and arranged to be able to provide a supply ofair at a positive pressure of at least 10 cmH₂O with respect to ambient.

The patient interface 3000 in accordance with one form of the presenttechnology is constructed and arranged to be able to provide a supply ofair at a positive pressure of at least 20 cmH₂O with respect to ambient.

5.3.1 Seal-Forming Structure

In one form of the present technology, a seal-forming structure 3100provides a target seal-forming region, and may additionally provide acushioning function. The target seal-forming region is a region on theseal-forming structure 3100 where sealing may occur. The region wheresealing actually occurs—the actual sealing surface—may change within agiven treatment session, from day to day, and from patient to patient,depending on a range of factors including for example, where the patientinterface was placed on the face, tension in the positioning andstabilising structure and the shape of a patient's face.

In one form the target seal-forming region is located on an outsidesurface of the seal-forming structure 3100.

In certain forms of the present technology, the seal-forming structure3100 is constructed from a biocompatible material, e.g. silicone rubber.

A seal-forming structure 3100 in accordance with the present technologymay be constructed from a soft, flexible, resilient material such assilicone.

In certain forms of the present technology, a system is providedcomprising more than one a seal-forming structure 3100, each beingconfigured to correspond to a different size and/or shape range. Forexample the system may comprise one form of a seal-forming structure3100 suitable for a large sized head, but not a small sized head andanother suitable for a small sized head, but not a large sized head.

5.3.1.1 Sealing Mechanisms

In one form, the seal-forming structure includes a sealing flangeutilizing a pressure assisted sealing mechanism. In use, the sealingflange can readily respond to a system positive pressure in the interiorof the plenum chamber 3200 acting on its underside to urge it into tightsealing engagement with the face. The pressure assisted mechanism mayact in conjunction with elastic tension in the positioning andstabilising structure.

In one form, the seal-forming structure 3100 comprises a sealing flangeand a support flange. The sealing flange comprises a relatively thinmember with a thickness of less than about 1 mm, for example about 0.25mm to about 0.45 mm, which extends around the perimeter of the plenumchamber 3200. Support flange may be relatively thicker than the sealingflange. The support flange is disposed between the sealing flange andthe marginal edge of the plenum chamber 3200, and extends at least partof the way around the perimeter. The support flange is or includes aspring-like element and functions to support the sealing flange frombuckling in use.

In one form, the seal-forming structure may comprise a compressionsealing portion or a gasket sealing portion. In use the compressionsealing portion, or the gasket sealing portion is constructed andarranged to be in compression, e.g. as a result of elastic tension inthe positioning and stabilising structure.

In one form, the seal-forming structure comprises a tension portion. Inuse, the tension portion is held in tension, e.g. by adjacent regions ofthe sealing flange.

In one form, the seal-forming structure comprises a region having atacky or adhesive surface.

In certain forms of the present technology, a seal-forming structure maycomprise one or more of a pressure-assisted sealing flange, acompression sealing portion, a gasket sealing portion, a tensionportion, and a portion having a tacky or adhesive surface.

5.3.1.2 Nose Bridge or Nose Ridge Region

In one form, the non-invasive patient interface 3000 comprises aseal-forming structure that forms a seal in use on a nose bridge regionor on a nose-ridge region of the patient's face.

In one form, the seal-forming structure includes a saddle-shaped regionconstructed to form a seal in use on a nose bridge region or on anose-ridge region of the patient's face.

5.3.1.3 Upper Lip Region

In one form, the non-invasive patient interface 3000 comprises aseal-forming structure that forms a seal in use on an upper lip region(that is, the lip superior) of the patient's face.

In one form, the seal-forming structure includes a saddle-shaped regionconstructed to form a seal in use on an upper lip region of thepatient's face.

5.3.1.4 Chin-Region

In one form the non-invasive patient interface 3000 comprises aseal-forming structure that forms a seal in use on a chin-region of thepatient's face.

In one form, the seal-forming structure includes a saddle-shaped regionconstructed to form a seal in use on a chin-region of the patient'sface.

5.3.1.5 Forehead Region

In one form, the seal-forming structure that forms a seal in use on aforehead region of the patient's face. In such a form, the plenumchamber may cover the eyes in use.

5.3.1.6 Nasal Pillows

In one form the seal-forming structure of the non-invasive patientinterface 3000 comprises a pair of nasal puffs, or nasal pillows, eachnasal puff or nasal pillow being constructed and arranged to form a sealwith a respective naris of the nose of a patient.

Nasal pillows in accordance with an aspect of the present technologyinclude: a frusto-cone, at least a portion of which forms a seal on anunderside of the patient's nose, a stalk, a flexible region on theunderside of the frusto-cone and connecting the frusto-cone to thestalk. In addition, the structure to which the nasal pillow of thepresent technology is connected includes a flexible region adjacent thebase of the stalk. The flexible regions can act in concert to facilitatea universal joint structure that is accommodating of relative movementboth displacement and angular of the frusto-cone and the structure towhich the nasal pillow is connected. For example, the frusto-cone may beaxially displaced towards the structure to which the stalk is connected.

5.3.1.7 Seal-Forming Structure 3100 of the Present Technology

The seal-forming structure 3100 according to examples of the presenttechnology may seal around the patient's nares and mouth separately,i.e., oro-nasal.

The seal-forming structure 3100 may include a nasal portion 3101 havinga nasal portion hole 3103 to seal with the patient's nares. The depictedexamples provide one nasal portion hole 3103 to provide the flow of airto both of the patient's nares. The nasal portion hole 3103, in analternative example, may be divided into two separate holes that eachcorresponds to one of the patient's nares, and part of the nasal portion3101 may separate the two separate holes.

The seal-forming structure 3100 may include an oral portion 3102 havingan oral portion hole 3104 to seal with the patient's mouth.

The seal-forming structure 3100 may at least partly form a patientinterface chamber 3001 that is pressurized by the flow of air. Theplenum chamber 3200 may be joined to the seal-forming structure 3100 tofurther form the patient interface chamber 3001.

5.3.2 Plenum Chamber

The plenum chamber 3200 has a perimeter that is shaped to becomplementary to the surface contour of the face of an average person inthe region where a seal will form in use. In use, a marginal edge of theplenum chamber 3200 is positioned in close proximity to an adjacentsurface of the face. Actual contact with the face is provided by theseal-forming structure 3100. The seal-forming structure 3100 may extendin use about the entire perimeter of the plenum chamber 3200. In someforms, the plenum chamber 3200 and the seal-forming structure 3100 areformed from a single homogeneous piece of material.

In certain forms of the present technology, the plenum chamber 3200 doesnot cover the eyes of the patient in use. In other words, the eyes areoutside the pressurised volume defined by the plenum chamber. Such formstend to be less obtrusive and/or more comfortable for the wearer, whichcan improve compliance with therapy.

In certain forms of the present technology, the plenum chamber 3200 isconstructed from a transparent material, e.g. a transparentpolycarbonate. The use of a transparent material can reduce theobtrusiveness of the patient interface, and help improve compliance withtherapy. The use of a transparent material can aid a clinician toobserve how the patient interface is located and functioning.

In certain forms of the present technology, the plenum chamber 3200 isconstructed from a translucent material. The use of a translucentmaterial can reduce the obtrusiveness of the patient interface, and helpimprove compliance with therapy.

The plenum chamber 3200 according to examples of the present technologymay include a plenum chamber hole 3201 on each lateral side. The plenumchamber 3201 may provide pneumatic communication between the conduitconnectors 3800, which are described in greater detail below, and thepatient interface chamber 3001. The plenum chamber 3200 may include aconnection rim 3202 around each plenum chamber hole 3201. The connectionrim 3202 may facilitate a mechanical connection, e.g., snap-fit orfriction fit, with the respective conduit connector. The plenum chamber3200 may be constructed of a sufficiently rigid material to provideaudible and/or tactile feedback to the patient when the conduitconnectors 3800 are connected to or removed from the plenum chamber3200.

The seal-forming structure 3100 may be connected to the plenum chamber3200. The connection may be permanent or the seal-forming structure 3100may be removable from the plenum chamber 3200. The seal-formingstructure 3100 may be overmoulded to the plenum chamber 3200. Theseal-forming structure 3100 and the plenum chamber 3200 may be joined bya mechanical interlock in which no chemical bond is formed between theplenum chamber 3200 and the seal-forming structure 3100.

5.3.3 Positioning and Stabilising Structure

The seal-forming structure 3100 of the patient interface 3000 of thepresent technology may be held in sealing position in use by thepositioning and stabilising structure 3300.

In one form the positioning and stabilising structure 3300 provides aretention force at least sufficient to overcome the effect of thepositive pressure in the plenum chamber 3200 to lift off the face.

In one form the positioning and stabilising structure 3300 provides aretention force to overcome the effect of the gravitational force on thepatient interface 3000.

In one form the positioning and stabilising structure 3300 provides aretention force as a safety margin to overcome the potential effect ofdisrupting forces on the patient interface 3000, such as from tube drag,or accidental interference with the patient interface.

In one form of the present technology, a positioning and stabilisingstructure 3300 is provided that is configured in a manner consistentwith being worn by a patient while sleeping. In one example thepositioning and stabilising structure 3300 has a low profile, orcross-sectional thickness, to reduce the perceived or actual bulk of theapparatus. In one example, the positioning and stabilising structure3300 comprises at least one strap having a rectangular cross-section. Inone example the positioning and stabilising structure 3300 comprises atleast one flat strap.

In one form of the present technology, a positioning and stabilisingstructure 3300 is provided that is configured so as not to be too largeand bulky to prevent the patient from lying in a supine sleepingposition with a back region of the patient's head on a pillow.

In one form of the present technology, a positioning and stabilisingstructure 3300 is provided that is configured so as not to be too largeand bulky to prevent the patient from lying in a side sleeping positionwith a side region of the patient's head on a pillow.

In one form of the present technology, a positioning and stabilisingstructure 3300 is provided with a decoupling portion located between ananterior portion of the positioning and stabilising structure 3300, anda posterior portion of the positioning and stabilising structure 3300.The decoupling portion does not resist compression and may be, e.g. aflexible or floppy strap. The decoupling portion is constructed andarranged so that when the patient lies with their head on a pillow, thepresence of the decoupling portion prevents a force on the posteriorportion from being transmitted along the positioning and stabilisingstructure 3300 and disrupting the seal.

In one form of the present technology, a positioning and stabilisingstructure 3300 comprises a strap constructed from a laminate of a fabricpatient-contacting layer, a foam inner layer and a fabric outer layer.In one form, the foam is porous to allow moisture, (e.g., sweat), topass through the strap. In one form, the fabric outer layer comprisesloop material to engage with a hook material portion.

In certain forms of the present technology, a positioning andstabilising structure 3300 comprises a strap that is extensible, e.g.resiliently extensible. For example the strap may be configured in useto be in tension, and to direct a force to draw a seal-forming structureinto sealing contact with a portion of a patient's face. In an examplethe strap may be configured as a tie.

In one form of the present technology, the positioning and stabilisingstructure comprises a first tie, the first tie being constructed andarranged so that in use at least a portion of an inferior edge thereofpasses superior to an otobasion superior of the patient's head andoverlays a portion of the parietal bone without overlaying the occipitalbone.

In one form of the present technology suitable for a nasal-only mask orfor a full-face mask, the positioning and stabilising structure includesa second tie, the second tie being constructed and arranged so that inuse at least a portion of a superior edge thereof passes inferior to anotobasion inferior of the patient's head and overlays or lies inferiorto the occipital bone of the patient's head.

In one form of the present technology suitable for a nasal-only mask orfor a full-face mask, the positioning and stabilising structure includesa third tie that is constructed and arranged to interconnect the firsttie and the second tie to reduce a tendency of the first tie and thesecond tie to move apart from one another.

In certain forms of the present technology, a positioning andstabilising structure 3300 comprises a strap that is bendable and e.g.non-rigid. An advantage of this aspect is that the strap is morecomfortable for a patient to lie upon while the patient is sleeping.

In certain forms of the present technology, a positioning andstabilising structure 3300 comprises a strap constructed to bebreathable to allow moisture vapour to be transmitted through the strap,

In certain forms of the present technology, a system is providedcomprising more than one positioning and stabilizing structure 3300,each being configured to provide a retaining force to correspond to adifferent size and/or shape range. For example the system may compriseone form of positioning and stabilizing structure 3300 suitable for alarge sized head, but not a small sized head, and another. suitable fora small sized head, but not a large sized head.

The positioning and stabilising structure 3300 may include a clip 3301to secure respective ties, e.g., to the conduit connectors 3800 as shownin FIGS. 32-36. The clip 3301 and the conduit connector 3800 may eachinclude a magnet 3305 arranged with opposing polarities to facilitate aconnection therebetween. The clip 3301 may also include a crossbar 3306around which the inferior ties 3303 are passed to secure the clips 3301thereto.

FIG. 66 depicts an exemplary positioning and stabilising structure 3300that may include superior ties 3302, inferior ties 3303, and a posteriorportion 3304.

5.3.4 Vent

In one form, the patient interface 3000 includes a vent 3400 constructedand arranged to allow for the washout of exhaled gases, e.g. carbondioxide.

In certain forms the vent 3400 is configured to allow a continuous ventflow from an interior of the plenum chamber 3200 to ambient whilst thepressure within the plenum chamber is positive with respect to ambient.The vent 3400 is configured such that the vent flow rate has a magnitudesufficient to reduce rebreathing of exhaled CO2 by the patient whilemaintaining the therapeutic pressure in the plenum chamber in use.

One form of vent 3400 in accordance with the present technologycomprises a plurality of holes, for example, about 20 to about 80 holes,or about 40 to about 60 holes, or about 45 to about 55 holes.

The vent 3400 may be located in the plenum chamber 3200. Alternatively,the vent 3400 is located in a decoupling structure, e.g., a swivel.

FIGS. 32 and 33 show an example of a vent 3400 provided on theconnection port 3600. Variations of these examples may exclude a vent3400 from the connection port 3600.

The conduit connectors 3800, which are described in greater detailbelow, may also include vent features.

5.3.5 Decoupling Structure(s)

In one form the patient interface 3000 includes at least one decouplingstructure, for example, a swivel or a ball and socket.

5.3.6 Connection Port

Connection port 3600 allows for connection to the air circuit 4170. Theconnection port 3600 according to an example of the present technologymay be connected to the connection port housing 3903. The connectionport 3600 may be swivelable relative to the connection port housing 3903and the connection to the air circuit 4170 may also be swivelable.

The connection port 3600 and the connection port housing 3903 may bepositioned superior to the patient's head in use.

FIGS. 37 and 38 show a connection port 3600 for the patient interface6000 according to another example of the present technology. While thepresent technology is described with reference to patient interface6000, it is to be understood that the technology is not limited to suchparticular example and may be adapted for use with other suitableinterface arrangements and types.

In the illustrated example, the connection port 3600 is in the form of aconnection port structured and arranged to provide a releasableconnection between the patient interface 6000 and the air circuit 4170.

The connection port 3600 comprises an elbow assembly 7700 configured toconnect to the air circuit 4170 (e.g., via a swivel connector 7790) anda ring member 7900 configured to connect to the patient interface 6000.As described in greater detail below, the elbow assembly 7700 isrepeatedly engageable with and removably disengageable from (i.e.,connectable to and disconnectable from) the ring member 7900 tofacilitate a releasable or separable connection between the rest of thepatient interface 3000 and the air circuit 4170.

5.3.6.1 Elbow Assembly

The elbow assembly 7700 includes an elbow member 7710 having a first endportion and a second end portion. In the illustrated example, the elbowmember 7710 includes a 90° bend such that the first end portion isgenerally perpendicular to the second end portion, i.e., central axis ofthe first end portion is at a 90° angle to the central axis of thesecond end portion. However, it should be appreciated that the first endportion and the second end portion may be arranged in alternativeconfigurations, e.g., arranged at non-perpendicular angle relative toone another.

A clip member 7730 is provided to the first end portion. In theillustrated example, the clip member 7730 is structured and arranged toprovide a releasable connection, e.g., releasable snap-fit connection orseparable snap joint assembly, with the ring member 7900. The second endportion is provided with the swivel connector 7790 (e.g., swivelconnector 7790 permanently connected to the second end portion) adaptedto connect to the air circuit 4170.

Also, a plurality of vent holes 7720 are provided along a rear wall ofthe elbow member 7710 (e.g., at least 10 vent holes, e.g., 10 to 20 ventholes) to permit the exit of exhaust gases from the patient interface3000. As illustrated, the vent holes 7720 are arranged in columns,however it should be appreciated that the vent holes may be arranged inother suitable manners, e.g., concentrically arranged. In an example,each vent hole 7720 may include a contour or taper along its length,e.g., each hole converges in the direction of exhausted gas. However,each vent hole 7720 may have other suitable shapes to direct exhaust orwashout gas. Further, in the illustrated example, the vent holes 7720may be positioned on a portion of the rear wall that is generally flator planar such that an exit end of each vent hole is provided along agenerally flat or planar surface. However, it should be appreciated thatthe vent holes 7720 may be positioned on a portion of the elbow member7710 having other shapes, e.g., rounded or convex.

The clip member 7730 includes a pair of resilient, quick release pincharms 7740 and a connecting portion 7760 that interconnects the pincharms 7740, i.e., pinch arm 7740 provided at each end of the connectingportion 7760.

Each of the pinch arms 7740 includes a catch portion 7750 and a buttonor trigger portion 7780. The pinch arms 7740 are structured and arrangedto provide a releasable snap-fit connection or separable snap jointassembly with the ring member 7900, e.g., catch portions 7750 configuredto deflect and snap into a recess or undercut on the ring member 7900.The button portions 7780 are structured and arranged to be manuallypinched or squeezed to deflect the catch portions 7750 for separation orrelease of the catch portions 7750 from the ring member 7900 and henceallow separation of the elbow assembly 7700 from the ring member 7900.

Each catch portion 7750 includes a barbed end, rib, or catch structuredto provide the snap joint assembly with the ring member 7900. Eachbutton or trigger portion 7780 includes a finger-grip portion 7781,e.g., recessed portion adjacent a free end of the pinch arm 7740.

In the illustrated example, the clip member 7730 and the elbow member7710 comprise separately molded components (i.e., separate and distinctstructures) that are subsequently connected to one another, e.g.,snap-fit connection. For example, the clip member 7730 may be comprisedof a material that is more flexible than a material of the elbow member7710, thereby allowing the clip member 7730 to flex onto and connect tothe first end portion of the elbow member 7710. In an example, aretaining arrangement is provided to connect or secure the clip memberto the elbow member, e.g., a snap-fit connection or snap joint assembly.

In the illustrated example, the clip member 7730 comprises an open-endedconfiguration with a semi-flexible and generally semi-circularconnecting portion 7760 which allows the clip member 7730 to beconnected to the elbow member 7710, e.g., in a manner similar to acirclip.

In an example, the catch portions 7750 of the clip member 7730 may bebiased inwards so that, when the clip member 7730 is connected to theelbow member 7710, the catch portions 7750 are biased inwards to gripthe elbow member 7710 and provide further resistance to removal from theelbow member 7710.

In the illustrated example, the elbow member 7710 and the clip member7730 provide a two-part assembly or construction. An exemplary advantageof such two-part construction is that it may allow manufacture withfewer restraints on materials. For example, the clip member 7730 and theelbow member 7710 comprise separately molded components so that there isless co-dependence between the clip member 7730 and the elbow member7710, e.g., clip member 7730 not subject to material constraints of theelbow member 7710. In an example, the clip member 7730 and the elbowmember 7710 comprise different materials and/or different materialproperties relative to one another. In an example, the clip member 7730and the elbow member 7710 are not molded in one piece from the samematerial.

In an example, the elbow member 7710 may be comprised of a material(e.g., polycarbonate) that is more rigid than a material of the clipmember 7730 (e.g., nylon-12). The material (e.g., nylon-12) of the clipmember 7730 may be relatively flexible and robust, e.g., facilitateflexing of the pinch arms, resistant to wear, maintain connection toelbow member. The material (e.g., polycarbonate) of the elbow member7710 may be relatively rigid, e.g., resistant to wear, clear tofacilitate cleaning, facilitate manufacturing.

Furthermore, the two-part construction may allow each part to be lesscomplex in geometry, resulting in an assembly that may allow simplertooling for manufacture.

In the illustrated example, the clip member 7730 is structured andarranged to provide a releasable connection, e.g., snap-fit connection,with the elbow member 7710. Such releasable or separable arrangement maybe advantageous to facilitate cleaning of the clip member 7730 and theelbow member 7710 when separated.

In an alternative example, the clip member 7730 may not be removablyconnected to the elbow member 7710, e.g., clip member may be permanentlyconnected to the elbow member. Such non-removable arrangement may beadvantageous as it reduces the possibly of the clip member being lost orbroken. Since the clip member is outside of the air flow path, athorough cleaning may not be as essential, e.g., compared to componentsexposed to the air flow path.

In an example, the clip member 7730 and the elbow member 7710 maycomprise separately molded components that are subsequently permanentlyconnected to one another such that the clip member 7730 may not beseparable from the elbow member 7710. Any suitable means may be employedto permanently join or connect the clip member and the elbow member.

In one example, the clip member 7730 and the elbow member 7710 may bewelded or bonded to one another, e.g., ultrasonically welded to oneanother. For example, the clip member 7730 may be connected to the elbowmember 7710 as described above, and then one or more portions (e.g., acenter portion) of the connecting portion 7760 of the clip member 7730may be welded or bonded to the elbow member 7710 to permanently securethe clip member to the elbow member. This connection would enable theconnecting portion to provide the torsion (and resistance to torsion)sufficient for operation of the pinch arms 7740.

Alternatively, the elbow assembly may be structured such that the clipmember can be easily assembled to the elbow member but structure of theelbow member and/or clip member makes disassembly difficult orchallenging. Such elbow assembly with separately manufactured elbowmember and clip member may achieve desired advantages (e.g., fewerrestraints on material selection) while avoiding the additional weldingor bonding operation to fix the clip member to the elbow member.

The ring member 7900 is configured to be removably and sealingly securedin the opening or aperture of the connection port housing 3903. Theelbow assembly 7700 releasably connects to the ring member 7900 via thepinch arms 7740, e.g., snap-fit or snap joint assembly.

The connection port 3600 provides decoupling of the air circuit 4170from the patient interface, e.g., to enhance the decoupling of tube dragon the patient interface to prevent seal instability.

One form of decoupling is provided by the pinch arms 7740 which form theswivel connection allowing 360° free rotation of the elbow assembly 7700relative to the ring member 7900. Another form of decoupling is providedby the swivel connector 7790 allowing 360° free rotation of the swivelconnector 7790 (and the air circuit 4170 connection thereto) relative tothe elbow member 7710.

5.3.7 Forehead Support

In one form, the patient interface 3000 includes a forehead support3700.

Examples of the patient interface of the present technology shown inFIGS. 7-36 do not include a forehead support. Variations of the patientinterface of the present technology may include a forehead support.

5.3.8 Conduits

The patient interface 3000 according to examples of the presenttechnology may include conduits 3900 to provide the flow of pressurizedfrom the connection port 3600 to the patient interface chamber 3001. Theconduits 3900 may be joined superior to the patient's head at theconnection port housing 3903 and may pass along lateral sides of thepatient's head between corresponding ones of the patient's eyes andears. The conduits 3900 may be connected to the plenum chamber 3200 viaconduit connectors 3800, as described below, to provide the flow ofpressurized air to the patient interface chamber 3001.

The conduits 3900 may also provide stabilize and position theseal-forming structure 3100 on the patient's face. Thus, the conduits3900 may function similarly to the ties of the positioning andstabilising structure 3300. Accordingly, the mechanical connection ofthe conduits 3900 to the conduit connectors 3800 may be sufficient fortension forces in the conduits 3900 to be transmitted to theseal-forming structure 3100 through the conduit connectors 3800.

The conduits 3900 may include features of similar conduits disclosed inInternational Application Publication No. WO 2017/124155 A1, which isincorporated by reference herein in its entirety. For example, theconduits 3900 of the present technology may include features of theheadgear tubes 3350 depicted in FIGS. 3A-3L of this document, as well asthe associated written description.

The conduits 3900 may also be provided with sleeves 3901 to cushion thepatient's face against the conduits 3900. The sleeves 3901 may beremovable. The sleeves 3901 may be made from a breathable material.

The conduits 3900 may also include tie connectors 3902 to facilitateconnection with ties of the positioning and stabilising structure 3300.

5.3.9 Conduit Connectors

The patient interface 3000, according to examples of the presenttechnology, may include conduit connectors 3800 to connect the conduits3900 to the plenum chamber 3200 to provide the flow of pressurized airto the patient interface chamber 3001. The conduit connectors 3800 mayeach be formed with a conduit connector housing 3801. The conduitconnectors 3800 may provide other functions, as described below, such asventing of the patient interface chamber 3001, connection to thepositioning and stabilising structure 3300, and asphyxia prevention byinclusion of an anti-asphyxia valve 3850.

FIGS. 7-18 show several views of the conduit connectors 3800 on thepatient interface 3000, according to examples of the present technology.FIGS. 25-31 show several views of the conduit connectors 3800, accordingto examples of the present technology, in isolation. FIGS. 32-36 showseveral views of the complete patient interface 3000 with the conduits3900 and the positioning and stabilising structure 3300 connected to theconduit connectors 3800, according to examples of the presenttechnology.

In FIGS. 7-18, the conduit connectors 3800 are shown attached to theplenum chamber 3200 at the plenum chamber holes 3201. As can be seen,there is one conduit connector 3800 on each lateral side of the patientinterface 3000, and each conduit connector 3800 is connected to a plenumchamber hole 3201 on each corresponding lateral side of the patientinterface 3000. The conduit connectors 3800 may each include a conduitconnector attachment structure 3807 to connect each of the conduitconnectors 3800 to a respective plenum chamber hole 3201 at theconnection rim 3202. The connection may be mechanical, e.g., snap-fit orfriction fit. The connection may also be removable. The material of theconduit connectors 3800 and the material of the plenum chamber 3200 mayeach be selected to facilitate the desired connection features. Forexample, the material of the conduit connectors 3800 and the material ofthe plenum chamber 3200 may each be relatively rigid to permit theaudible and/or tactile feedback associated with a snap-fit. The materialof the conduit connectors 3800 and the material of the plenum chamber3200 may be different in at least one aspect or the materials may be thesame. The conduit connectors 3800 may also be permanently connected tothe plenum chamber 3200 at the plenum chamber holes 3201. For example,the conduit connectors 3800 may be ultrasonically welded to the plenumchamber 3200 at the plenum chamber holes 3201. The connection betweenthe conduit connectors 3800 and the plenum chamber 3200, whetherremovable or permanent, may also be designed to be sufficiently strongsuch that tension from the conduits 3900 can be transferred to theplenum chamber 3200 without disrupting the connection because, asexplained above, the conduit connectors 3800 may facilitate positioningand stabilising of the seal-forming structure 3100 on the patient'shead.

The conduit connectors 3800 may also be attached to lateral sides of theplenum chamber 3200 to improve aesthetics of the patient interface 3000.As explained above, the plenum chamber 3200 may be constructed of atransparent or translucent material, which may allow visibility of thepatient's facial features. By locating the conduit connectors 3800laterally on the plenum chamber, e.g., as shown in the depictedexamples, more of the patient's face is visible, and that arrangementcan improve aesthetics of the patient interface 3000. This contrastswith alternative designs where an elbow and air circuit may be joined tothe center of the plenum chamber 3200, thereby obstructing the view ofthe patient's face.

The conduit connectors 3800 and the plenum chamber holes 3201 may alsobe arranged so that at least a portion of the conduit connector housing3801 extends into the patient interface chamber 3001. This arrangementmay reduce the dead space within the patient interface chamber 3001 bymaking use of volume within the patient interface chamber 3001 with theconduit connectors 3800. Accordingly, less of the conduit connectors3800 overall volume extends outwardly from the patient interface 3000.This may be advantageous because it reduces the excess structures thatare susceptible to being caught on bedding, and it provide a sleekeraesthetic for the patient that may be more visually appealing.

The conduit connectors 3800 may also each include a conduit connectionend 3802 that connects to a respective conduit 3900. The connectionbetween the conduits 3900 and the conduit connectors 3800 at the conduitconnection ends 3802 may be removable or permanent. A conduit connectorinlet hole 3803 may be formed in the conduit connector housing 3801 atthe conduit connection end 3802 to receive the flow of pressurized air.The conduit connectors 3800 may include structure, e.g., an undercut, tofacilitate a removable, snap-fit connection with corresponding conduits3900, and each conduit 3900 may include a relatively rigid structure atthe end that connects to the conduit connectors 3800 to facilitate sucha connection. The conduit connectors 3800 may also be joined to theconduits 3900 with a friction fit. Again, as explained above, theconduits 3900 may provide a positioning and stabilising function tolocate the seal-forming structure in a therapeutically effective sealingposition on the patient's face, and therefore the connection between theconduits 3900 and the conduit connectors 3800 at the conduit connectionends 3802 may be sufficiently secure to permit tension forces from theconduits 3900 to be transmitted to the conduit connectors 3800 withoutdisrupting the connection between the conduits 3900 and the conduitconnectors 3800 at the conduit connection ends 3802.

The conduit connectors 3800 may also provide a venting function for thepatient interface 3000. The conduit connector housing 3801 may include aconduit connector vent inlet 3832 that is in pneumatic communicationwith the patient interface chamber 3001 when the patient interface 3000is assembled. The conduit connector housing 3801 may also include atleast one conduit connector vent hole 3831. As can be seen in thedepicted examples, each conduit connector housing 3801 includes aplurality of conduit connector vent holes 3831. The conduit connectorhousing 3801 may also include a baffle 3805 to prevent air entering thepatient interface chamber 3001 via the conduit connector outlet hole3804 from escaping directly out the conduit connector vent hole(s) 3831.This ensures adequate mixing of newly introduced air and air alreadypresent in the patient interface chamber 3001, which can enhance carbondioxide washout and increase the amount of fresh air provided to thepatient for respiration. The conduit connector housing 3801 may alsoinclude at least one conduit connector vent spacer 3833—FIGS. 25-31 showa plurality of conduit connector vent spacers 3833 in these examples—toprovide a passageway for exhaled gas to escape to atmosphere from theconduit connectors 3800 via a conduit connector vent outlet 3830. Theconduit connector vent spacers 3833 may be distributed around a portionof the perimeter of the conduit connector housing 3801. The conduitconnector vent spacers 3833 may maintain spacing between a portion ofthe conduit connector housing 3801 and the plenum chamber 3200 for theconduit connector vent outlet 3830.

The conduit connector housing 3801 may also include a diffuser cavity3871 that may contain diffuser material (not shown). The diffusermaterial may be enclosed within the diffuser cavity 3871 by a diffusercover 3870. The diffuser cover 3870 may be permanently attached to theconduit connector housing 3801, which prevents the patient from changingthe diffuser material if it becomes occluded due to contaminants. Inthis example, the diffuser cover 3870 may be ultrasonically welded tothe conduit connector housing 3801. Alternatively, the diffuser cover3870 may be removably attached to the conduit connector housing 3801,e.g., via a snap-fit or a friction fit, which would permit the patientto replace the diffuser material.

As shown in FIGS. 32-36, the conduit connectors 3800 may also provide aconnection to ties of the positioning and stabilising structure 3300.The inferior ties may be joined to the conduit connectors 3800 withclips 3301. The clips 3301 and the conduit connectors 3800 may includemagnets with opposing polarities to facilitate the connection. Theconnection between the ties of the positioning and stabilising structure3300 and the conduit connectors 3800 may be releasable. The tension fromthe inferior ties of the positioning and stabilising structure 3300 mayurge inferior portions of the seal-forming structure 3100 into sealingengagement with the patient's face, e.g., around the mouth. Although notshown in FIGS. 25-31, structure to connect to the clips 3301 may beformed on the diffuser cover 3870. Alternatively, structure to connectto the clips 3301 may be formed directly on the conduit connectorhousing 3801.

FIGS. 39-66 depict another example of the present technology thatincludes features similar to the example depicted in FIGS. 7-36. Theexample in FIGS. 39-66 also includes features that are different fromthe example depicted in FIGS. 7-36.

As can be seen in the example depicted in FIGS. 39-66, the plenumchamber 3200 includes a plurality of plenum chamber vent holes 3401 topermit the discharge of gas, including exhaled carbon dioxide, from thepatient interface chamber 3001 to atmosphere. Accordingly, the conduitconnectors 3800 of this example do not include any venting structures(i.e., conduit connector vent outlet 3830, conduit connector vent hole3831, conduit connector vent inlet 3832, etc.) present in the precedingexample because the plenum chamber vent holes 3401 can be sized, shaped,and a large enough number provided to permit sufficient carbon dioxidewashout.

In an alternative example, the conduit connectors 3800 may include theconduit connector vent outlet 3830, conduit connector vent hole 3831,conduit connector vent inlet 3832, etc., while the plurality of plenumchamber vent holes 3401 are also provided on the plenum chamber 3200.This arrangement may be advantageous in that it may provide additionaland/or more diffuse venting.

Although the conduit connectors 3800 of this example do not include anyventing structures (i.e., conduit connector vent outlet 3830, theanti-asphyxia valve assembly 3850 is still provided to each of theconduit connectors 3800 for safety reasons. FIGS. 46 and 47 showmovement of the anti-asphyxia valve flap 3851 between open and closedpositions, similar to the example described above.

In the example of FIGS. 39-66, the plenum chamber 3200 may have nosealing structure on the plenum chamber holes 3201. In this example,sealing between the conduit connectors 3800 and the plenum chamber 3200may be accomplished with conduit connector outlet seal 3861 joinedaround the exterior perimeter of the conduit connector outlet 3808. Theconduit connector outlet seal 3861 may be constructed of an elastomericmaterial, e.g., silicone, that deforms upon contact with a connectionrim 3202 around each plenum chamber hole 3201. The conduit connectoroutlet seal 3861 may be overmolded to the conduit connector outlet 3808.When the conduit connectors 3800 are attached to corresponding plenumchamber holes 3201, the conduit connector outlet seals 3861 deformagainst the connection rim 3202 and ensure sealing therebetween. Theconduit connector outlet seal 3861 in this example may extend around theentirety of the conduit connector outlet 3808 or the conduit connectoroutlet seal 3861 may only be provided at one or more selected portionsaround the conduit connector outlet 3808.

Alternatively, it is also contemplated that the conduit connector outletseal 3861 is provided to the connection rim 3202 of each plenum chamberhole 3201 to be deformed against the conduit connector outlet 3808 ofeach conduit connector 3800. The conduit connector outlet seal 3861 inthis example may extend around the entirety of the plenum chamber hole3201 or the conduit connector outlet seal 3861 may only be provided atone or more selected portions around the plenum chamber hole 3201.

In a further alternative example, there may be no deformable sealingcomponent between the conduit connector 3800 and the connection rim 3202of the corresponding plenum chamber hole 3201. Thus, leak may bepermitted in this alternative or the tolerances between the conduitconnector 3800 and the connection rim 3202 of the corresponding plenumchamber hole 3201 may be so small as to permit little or no leak.

In the example of FIGS. 39-66, the conduit connectors 3800 may beconfigured to provide a releasable connection to the plenum chamber 3200at the corresponding plenum chamber hole 3201. The conduit connectors3800 may be constructed of a relatively rigid, plastic material, e.g.,polycarbonate, to facilitate the connection described below.

A slot 3203 and a detent 3204 may be formed on the plenum chamber 3200at each plenum chamber hole 3201 to engage with corresponding structuresof the conduit connectors 3800. The engagement process may begin byengaging a first tab 3890 with the slot 3203 from an anterior side(i.e., facing away from the patient in use) of the plenum chamber 3200.The first tab 3890 may be relatively rigid and its engagement with theslot 3203 may act as a fulcrum so that the conduit connector 3800 canthen be rotated about the slot 3203 to complete the engagement process.The engagement process may be completed by a second tab 3891 having acatch 3892 engaging the detent 3204 of the plenum chamber 3204. As theconduit connector 3800 is rotated into engagement with the plenumchamber 3200 in the corresponding plenum chamber hole 3201, the conduitconnector outlet seal 3861 may engage the corresponding connection rim3202 to establish a pneumatic seal. Additionally, the conduit connectoroutlet 3808 may extend, at least partially, through the correspondingplenum chamber hole 3201 so that gas can travel between the patientinterface chamber 3001 and the conduit connector 3800. The second tab3891 may be flexible so that when the catch 3892 and the detent 3204come into engagement a snap-fit connection is established. This may bebeneficial for the patient because the snap-fit connection providestactile and audible feedback that the connection is established. Gaps3893 on either side of the second tab 3891 and between the conduitconnector outlet 3808 allow the second tab 3891 to be cantilevered foreasier deformation during the engagement and disengagement processes.

The disengagement process happens in the opposite order by firstdisengaging the catch 3892 from the corresponding detent 3204 byrotating the conduit connector 3800 in an anterior direction away fromthe plenum chamber 3200. Since the second tab 3891 is flexible, oncesufficient force is applied the second tab will deflect and allow thecatch 3892 to disengage from the detent 3204. The conduit connector 3800is then rotated further so that the first tab 3890 disengages from theslot 3203. During the disengagement process, the conduit connectoroutlet seal 3861 also disengages from the corresponding connection rim3202 and the conduit connector outlet 3808 exits the correspondingplenum chamber hole 3201.

When engaged, the conduit connector 3800 may protrude in an anteriordirection relative to the plenum chamber 3200 such that the conduits3900 are directed laterally away from the plenum chamber 3200. Bylocating the conduits 3900 forward of the plenum chamber 3200, theconduits 3900 may remain engaged and undamaged when lateral forces pullthe conduits 3900 away from the plenum chamber 3200, while also loweringthe force required to disengage the conduit connectors 3800, andtherefore also the conduits 3900, from the plenum chamber 3200. Thus,the conduits 3900, as will be discussed further below, may be joined tothe conduit connectors 3800 with sufficient strength to resistdisengagement in a lateral direction, while also allowing the conduitconnectors 3800 to be relatively easily removed from the plenum chamber3200 by rotating out of the plenum chamber holes 3201, as describedabove. This arrangement may be beneficial in the typical use casebecause lateral forces may be common during use, i.e., sleep, and it isadvantageous to ensure that the patient interface 3000 can resist theseforces without disrupting the connection between the conduits 3900 andthe plenum chamber 3200, and therefore the flow of gas. However, forcesthat would cause the disengagement process described above to occur areless common during sleep. Accordingly, the first tab 3890 and the secondtab 3891 can be designed to engage and disengage from the slot 3203 anddetent 3204 with relatively low force in the respective directions,which in turn allows the patient to easily engage and disengage theconduit connectors 3800. The disengagement force in this example may beas low as 8 to 12 Newtons.

Additionally, the force required to disengage the conduit connectors3800 may be sufficiently low that the conduit connectors 3800 may bedisengaged by application of a force in an anterior direction on aflange 3885 configured for magnetic fastening of positioning andstabilising structure 3300.

The conduit connector 3800 may also include a flange 3885 to connect theinferior ties 3303 to the conduit connector 3800 via clips 3301. Theflange 3885 may extend from the conduit connector 3800. The flange 3885may be molded in one piece with the conduit connector 3800. The flange3885 may include a flange opening 3887 and a recess 3886 to receive atab connector 3884 of an inferior tie tab 3880. To attach the inferiortie tab 3880 to the flange 3885, the tab connector 3884 passes throughthe flange opening 3887 and engages in the recess 3886. The inferior tietab 3880 may include a clip receiver 3881 that may house a magnet toprovide a releasable connection to a corresponding magnet in a clip3301. The clip receiver 3881 may also engage with an overhang 3307 ofthe clip 3301 to ensure that the clip 3301 remains engaged with theinferior tie tab 3880. Thus, attraction between the magnets of the clip3301 and the clip receiver 3881 may provide a locating function whileengagement of the overhang 3307 and the clip receiver 3881 ensure thatthe clip 3301 remains securely connected to the inferior tie tab 3880.It should be understood that the connection between the clip 3301 andthe inferior tie tab 3880 is releasable by applying force sufficient toovercome the attraction between the two magnets. The inferior tie tab3880 may also include a notch 3882.

The conduit 3900 may be joined to the conduit connector 3800 at theconduit connector end 3802 permanently or removably. FIG. 63 depicts anexample of a permanent connection whereby an intermediate conduitconnector inlet seal 3860, e.g., of silicone, is molded around theconduit connector end 3802. The conduit 3900, which may also besilicone, is molded onto the intermediate conduit connector inlet seal3860.

5.3.10 Anti-Asphyxia Valve

In one form, the patient interface 3000 includes an anti-asphyxia valve.As can be seen in the examples depicted in FIGS. 7-18 and 25-31, each ofthe conduit connectors 3800 may include an anti-asphyxia valve assembly3850. Accordingly, the patient interface 3000 may include twoanti-asphyxia valve assemblies 3850. Each of the anti-asphyxia valveassemblies 3850 may operate independent of the other, i.e., in responseto a cessation of the flow of pressurized air. For example, if thepatient is sleeping on his or her side when there is a cessation of theflow of pressurized air and one of the anti-asphyxia valve assemblies3850 is occluded, e.g., by a pillow, the other of the anti-asphyxiavalve assemblies 3850 can function to prevent the patient from beingasphyxiated.

The anti-asphyxia valve assembly 3850 may include an anti-asphyxia valveflap 3851 that covers an anti-asphyxia valve hole 3852 in a closedposition. The cross-sectional view of FIGS. 14 and 29 depict theanti-asphyxia valve flap 3851 in the closed position. In these views, itcan be seen that the flow of pressurized air entering the conduitconnectors 3800 will be prevented from escaping to atmosphere throughthe anti-asphyxia valve hole 3852 by the anti-asphyxia valve flap 3851and will be directed into the patient interface chamber 3001 by theconduit connector outlet hole 3804. The anti-asphyxia valve flap 3851may be configured to remain in the closed position during the patient'sentire respiratory cycle, i.e., inhalation and exhalation. Thus, thepatient receives the flow of pressurized air to their airways to ensurethat patient's airways maintain sufficient patency during inhalation andexhalation. FIGS. 15 and 30 depict the anti-asphyxia valve flap 3851 inan open position in which the anti-asphyxia valve hole 3852 is notcovered such that the patient can breathe from atmosphere via theanti-asphyxia valve hole 3852, if there is a cessation of the flow ofpressurized air. Moreover, the anti-asphyxia valve flap 3851 may beconstructed such that the open position may be the default, neutral, orundeformed position so that only when the pressurized flow of air, atleast to a minimum flow rate and/or pressure, is applied is theanti-asphyxia valve flap 3851 moved to the closed position by the forceof the pressure and/or flow of the air. Additionally, the anti-asphyxiavalve hole 3852 may be sized sufficiently so that if one of theanti-asphyxia valve assemblies 3850 is occluded and prevented frompermitting respiration, the patient can breathe adequately through thenon-occluded anti-asphyxia valve assembly 3850. Furthermore, theanti-asphyxia valve flap 3851 may be sized so as to completely occludethe anti-asphyxia valve hole 3852 in the closed position. Alternatively,the anti-asphyxia valve flap 3851 may include holes that allow air topass through to atmosphere, e.g., for venting, in the closed position.

The anti-asphyxia valve flap 3851 may be joined to the conduit connectorhousing 3801 with an anti-asphyxia valve flap connector 3854 thatextends into an anti-asphyxia valve flap connector hole 3853. Theanti-asphyxia valve flap 3851 may be permanently attached to the conduitconnector housing 3801 at the anti-asphyxia valve flap connector hole3853 by being overmoulded onto the conduit connector housing 3801. Theanti-asphyxia valve flap 3851 may be made of a flexible, elasticmaterial that allows it to be deflected from the open position to theclosed position by the force of the pressure and/or flow of the air.

The an anti-asphyxia valve assembly 3850 may also include ananti-asphyxia valve hole divider 3855 across the anti-asphyxia valvehole 3852. The anti-asphyxia valve hole divider 3855 may prevent theanti-asphyxia valve flap 3851 from being pushed out the anti-asphyxiavalve hole 3852 due to pressure within the patient interface chamber3001.

5.3.11 Ports

In one form of the present technology, a patient interface 3000 includesone or more ports that allow access to the volume within the plenumchamber 3200. In one form this allows a clinician to supply supplementaloxygen. In one form, this allows for the direct measurement of aproperty of gases within the plenum chamber 3200, such as the pressure.

5.4 RPT Device

An RPT device 4000 in accordance with one aspect of the presenttechnology comprises mechanical, pneumatic, and/or electrical componentsand is configured to execute one or more algorithms, such as any of themethods, in whole or in part, described herein. The RPT device 4000 maybe configured to generate a flow of air for delivery to a patient'sairways, such as to treat one or more of the respiratory conditionsdescribed elsewhere in the present document.

In one form, the RPT device 4000 is constructed and arranged to becapable of delivering a flow of air in a range of −20 L/min to +150L/min while maintaining a positive pressure of at least 6 cmH₂O, or atleast 10cmH₂O, or at least 20 cmH₂O.

The RPT device may have an external housing 4010, formed in two parts,an upper portion 4012 and a lower portion 4014. Furthermore, theexternal housing 4010 may include one or more panel(s) 4015. The RPTdevice 4000 comprises a chassis 4016 that supports one or more internalcomponents of the RPT device 4000. The RPT device 4000 may include ahandle 4018.

The pneumatic path of the RPT device 4000 may comprise one or more airpath items, e.g., an inlet air filter 4112, an inlet muffler 4122, apressure generator 4140 capable of supplying air at positive pressure(e.g., a blower 4142), an outlet muffler 4124 and one or moretransducers 4270, such as pressure sensors 4272 and flow rate sensors4274.

One or more of the air path items may be located within a removableunitary structure which will be referred to as a pneumatic block 4020.The pneumatic block 4020 may be located within the external housing4010. In one form a pneumatic block 4020 is supported by, or formed aspart of the chassis 4016.

The RPT device 4000 may have an electrical power supply 4210, one ormore input devices 4220, a central controller 4230, a therapy devicecontroller 4240, a pressure generator 4140, one or more protectioncircuits 4250, memory 4260, transducers 4270, data communicationinterface 4280 and one or more output devices 4290. Electricalcomponents 4200 may be mounted on a single Printed Circuit BoardAssembly (PCBA) 4202. In an alternative form, the RPT device 4000 mayinclude more than one PCBA 4202.

5.4.1 RPT Device Mechanical & Pneumatic Components

An RPT device may comprise one or more of the following components in anintegral unit. In an alternative form, one or more of the followingcomponents may be located as respective separate units.

5.4.1.1 Air Filter(s)

An RPT device in accordance with one form of the present technology mayinclude an air filter 4110, or a plurality of air filters 4110.

In one form, an inlet air filter 4112 is located at the beginning of thepneumatic path upstream of a pressure generator 4140.

In one form, an outlet air filter 4114, for example an antibacterialfilter, is located between an outlet of the pneumatic block 4020 and apatient interface 3000.

5.4.1.2 Muffler(s)

An RPT device in accordance with one form of the present technology mayinclude a muffler 4120, or a plurality of mufflers 4120.

In one form of the present technology, an inlet muffler 4122 is locatedin the pneumatic path upstream of a pressure generator 4140.

In one form of the present technology, an outlet muffler 4124 is locatedin the pneumatic path between the pressure generator 4140 and a patientinterface 3000.

5.4.1.3 Pressure Generator

In one form of the present technology, a pressure generator 4140 forproducing a flow, or a supply, of air at positive pressure is acontrollable blower 4142. For example the blower 4142 may include abrushless DC motor 4144 with one or more impellers housed in a blowerhousing, such as in a volute. The blower may be capable of delivering asupply of air, for example at a rate of up to about 120 litres/minute,at a positive pressure in a range from about 4 cmH₂O to about 20 cmH₂O,or in other forms up to about 30 cmH₂O. The blower may be as describedin any one of the following patents or patent applications the contentsof which are incorporated herein by reference in their entirety: U.S.Pat. Nos. 7,866,944; 8,638,014; 8,636,479; and PCT Patent ApplicationPublication No. WO 2013/020167.

The pressure generator 4140 is under the control of the therapy devicecontroller 4240.

In other forms, a pressure generator 4140 may be a piston-driven pump, apressure regulator connected to a high pressure source (e.g. compressedair reservoir), or a bellows.

5.4.1.4 Transducer(s)

Transducers may be internal of the RPT device, or external of the RPTdevice. External transducers may be located for example on or form partof the air circuit, e.g., the patient interface. External transducersmay be in the form of non-contact sensors such as a Doppler radarmovement sensor that transmit or transfer data to the RPT device.

In one form of the present technology, one or more transducers 4270 arelocated upstream and/or downstream of the pressure generator 4140. Theone or more transducers 4270 may be constructed and arranged to generatesignals representing properties of the flow of air such as a flow rate,a pressure or a temperature at that point in the pneumatic path.

In one form of the present technology, one or more transducers 4270 maybe located proximate to the patient interface 3000.

In one form, a signal from a transducer 4270 may be filtered, such as bylow-pass, high-pass or band-pass filtering.

5.4.1.4.1 Flow Rate Sensor

A flow rate sensor 4274 in accordance with the present technology may bebased on a differential pressure transducer, for example, an SDP600Series differential pressure transducer from SENSIRION.

In one form, a signal representing a flow rate from the flow rate sensor4274 is received by the central controller 4230.

5.4.1.4.2 Pressure Sensor

A pressure sensor 4272 in accordance with the present technology islocated in fluid communication with the pneumatic path. An example of asuitable pressure sensor is a transducer from the HONEYWELL ASDX series.An alternative suitable pressure sensor is a transducer from the NPASeries from GENERAL ELECTRIC.

In one form, a signal from the pressure sensor 4272 is received by thecentral controller 4230.

5.4.1.4.3 Motor Speed Transducer

In one form of the present technology a motor speed transducer 4276 isused to determine a rotational velocity of the motor 4144 and/or theblower 4142. A motor speed signal from the motor speed transducer 4276may be provided to the therapy device controller 4240. The motor speedtransducer 4276 may, for example, be a speed sensor, such as a Halleffect sensor.

5.4.1.5 Anti-Spill Back Valve

In one form of the present technology, an anti-spill back valve 4160 islocated between the humidifier 5000 and the pneumatic block 4020. Theanti-spill back valve is constructed and arranged to reduce the riskthat water will flow upstream from the humidifier 5000, for example tothe motor 4144.

5.4.2 RPT Device Electrical Components

5.4.2.1 Power Supply

A power supply 4210 may be located internal or external of the externalhousing 4010 of the RPT device 4000.

In one form of the present technology, power supply 4210 provideselectrical power to the RPT device 4000 only. In another form of thepresent technology, power supply 4210 provides electrical power to bothRPT device 4000 and humidifier 5000.

5.4.2.2 Input Devices

In one form of the present technology, an RPT device 4000 includes oneor more input devices 4220 in the form of buttons, switches or dials toallow a person to interact with the device. The buttons, switches ordials may be physical devices, or software devices accessible via atouch screen. The buttons, switches or dials may, in one form, bephysically connected to the external housing 4010, or may, in anotherform, be in wireless communication with a receiver that is in electricalconnection to the central controller 4230.

In one form, the input device 4220 may be constructed and arranged toallow a person to select a value and/or a menu option.

5.4.2.3 Central Controller

In one form of the present technology, the central controller 4230 isone or a plurality of processors suitable to control an RPT device 4000.

Suitable processors may include an x86 INTEL processor, a processorbased on ARM® Cortex®-M processor from ARM Holdings such as an STM32series microcontroller from ST MICROELECTRONIC. In certain alternativeforms of the present technology, a 32-bit RISC CPU, such as an STR9series microcontroller from ST MICROELECTRONICS or a 16-bit RISC CPUsuch as a processor from the MSP430 family of microcontrollers,manufactured by TEXAS INSTRUMENTS may also be suitable.

In one form of the present technology, the central controller 4230 is adedicated electronic circuit.

In one form, the central controller 4230 is an application-specificintegrated circuit. In another form, the central controller 4230comprises discrete electronic components.

The central controller 4230 may be configured to receive input signal(s)from one or more transducers 4270, one or more input devices 4220, andthe humidifier 5000.

The central controller 4230 may be configured to provide outputsignal(s) to one or more of an output device 4290, a therapy devicecontroller 4240, a data communication interface 4280, and the humidifier5000.

In some forms of the present technology, the central controller 4230 isconfigured to implement the one or more methodologies described herein,such as the one or more algorithms expressed as computer programs storedin a non-transitory computer readable storage medium, such as memory4260. In some forms of the present technology, the central controller4230 may be integrated with an RPT device 4000. However, in some formsof the present technology, some methodologies may be performed by aremotely located device. For example, the remotely located device maydetermine control settings for a ventilator or detect respiratoryrelated events by analysis of stored data such as from any of thesensors described herein.

5.4.2.4 Clock

The RPT device 4000 may include a clock 4232 that is connected to thecentral controller 4230.

5.4.2.5 Therapy Device Controller

In one form of the present technology, therapy device controller 4240 isa therapy control module that forms part of the algorithms executed bythe central controller 4230.

In one form of the present technology, therapy device controller 4240 isa dedicated motor control integrated circuit. For example, in one form aMC33035 brushless DC motor controller, manufactured by ONSEMI is used.

5.4.2.6 Protection Circuits

The one or more protection circuits 4250 in accordance with the presenttechnology may comprise an electrical protection circuit, a temperatureand/or pressure safety circuit.

5.4.2.7 Memory

In accordance with one form of the present technology the RPT device4000 includes memory 4260, e.g., non-volatile memory. In some forms,memory 4260 may include battery powered static RAM. In some forms,memory 4260 may include volatile RAM.

Memory 4260 may be located on the PCBA 4202. Memory 4260 may be in theform of EEPROM, or NAND flash.

Additionally or alternatively, RPT device 4000 includes a removable formof memory 4260, for example a memory card made in accordance with theSecure Digital (SD) standard.

In one form of the present technology, the memory 4260 acts as anon-transitory computer readable storage medium on which is storedcomputer program instructions expressing the one or more methodologiesdescribed herein, such as the one or more algorithms.

5.4.2.8 Data Communication Systems

In one form of the present technology, a data communication interface4280 is provided, and is connected to the central controller 4230. Datacommunication interface 4280 may be connectable to a remote externalcommunication network 4282 and/or a local external communication network4284. The remote external communication network 4282 may be connectableto a remote external device 4286. The local external communicationnetwork 4284 may be connectable to a local external device 4288.

In one form, data communication interface 4280 is part of the centralcontroller 4230. In another form, data communication interface 4280 isseparate from the central controller 4230, and may comprise anintegrated circuit or a processor.

In one form, remote external communication network 4282 is the Internet.The data communication interface 4280 may use wired communication (e.g.via Ethernet, or optical fibre) or a wireless protocol (e.g. CDMA, GSM,LTE) to connect to the Internet.

In one form, local external communication network 4284 utilises one ormore communication standards, such as Bluetooth, or a consumer infraredprotocol.

In one form, remote external device 4286 is one or more computers, forexample a cluster of networked computers. In one form, remote externaldevice 4286 may be virtual computers, rather than physical computers. Ineither case, such a remote external device 4286 may be accessible to anappropriately authorised person such as a clinician.

The local external device 4288 may be a personal computer, mobile phone,tablet or remote control.

5.4.2.9 Output Devices Including Optional Display, Alarms

An output device 4290 in accordance with the present technology may takethe form of one or more of a visual, audio and haptic unit. A visualdisplay may be a Liquid Crystal Display (LCD) or Light Emitting Diode(LED) display.

5.4.2.9.1 Display Driver

A display driver 4292 receives as an input the characters, symbols, orimages intended for display on the display 4294, and converts them tocommands that cause the display 4294 to display those characters,symbols, or images.

5.4.2.9.2 Display

A display 4294 is configured to visually display characters, symbols, orimages in response to commands received from the display driver 4292.For example, the display 4294 may be an eight-segment display, in whichcase the display driver 4292 converts each character or symbol, such asthe figure “0”, to eight logical signals indicating whether the eightrespective segments are to be activated to display a particularcharacter or symbol.

5.5 Air Circuit

An air circuit 4170 in accordance with an aspect of the presenttechnology is a conduit or a tube constructed and arranged to allow, inuse, a flow of air to travel between two components such as RPT device4000 and the patient interface 3000.

In particular, the air circuit 4170 may be in fluid connection with theoutlet of the pneumatic block 4020 and the patient interface. The aircircuit may be referred to as an air delivery tube. In some cases theremay be separate limbs of the circuit for inhalation and exhalation. Inother cases a single limb is used.

In some forms, the air circuit 4170 may comprise one or more heatingelements configured to heat air in the air circuit, for example tomaintain or raise the temperature of the air. The heating element may bein a form of a heated wire circuit, and may comprise one or moretransducers, such as temperature sensors. In one form, the heated wirecircuit may be helically wound around the axis of the air circuit 4170.The heating element may be in communication with a controller such as acentral controller 4230. One example of an air circuit 4170 comprising aheated wire circuit is described in U.S. Pat. No. 8,733,349, which isincorporated herewithin in its entirety by reference.

5.5.1 Oxygen Delivery

In one form of the present technology, supplemental oxygen 4180 isdelivered to one or more points in the pneumatic path, such as upstreamof the pneumatic block 4020, to the air circuit 4170 and/or to thepatient interface 3000.

5.6 Humidifier

5.6.1 Humidifier Overview

In one form of the present technology there is provided a humidifier5000 (e.g. as shown in FIG. 5A) to change the absolute humidity of airor gas for delivery to a patient relative to ambient air. Typically, thehumidifier 5000 is used to increase the absolute humidity and increasethe temperature of the flow of air (relative to ambient air) beforedelivery to the patient's airways.

The humidifier 5000 may comprise a humidifier reservoir 5110, ahumidifier inlet 5002 to receive a flow of air, and a humidifier outlet5004 to deliver a humidified flow of air. In some forms, as shown inFIG. 5A and FIG. 5B, an inlet and an outlet of the humidifier reservoir5110 may be the humidifier inlet 5002 and the humidifier outlet 5004respectively. The humidifier 5000 may further comprise a humidifier base5006, which may be adapted to receive the humidifier reservoir 5110 andcomprise a heating element 5240.

5.6.2 Humidifier Components

5.6.2.1 Water Reservoir

According to one arrangement, the humidifier 5000 may comprise a waterreservoir 5110 configured to hold, or retain, a volume of liquid (e.g.water) to be evaporated for humidification of the flow of air. The waterreservoir 5110 may be configured to hold a predetermined maximum volumeof water in order to provide adequate humidification for at least theduration of a respiratory therapy session, such as one evening of sleep.Typically, the reservoir 5110 is configured to hold several hundredmillilitres of water, e.g. 300 millilitres (ml), 325 ml, 350 ml or 400ml. In other forms, the humidifier 5000 may be configured to receive asupply of water from an external water source such as a building's watersupply system.

According to one aspect, the water reservoir 5110 is configured to addhumidity to a flow of air from the RPT device 4000 as the flow of airtravels therethrough. In one form, the water reservoir 5110 may beconfigured to encourage the flow of air to travel in a tortuous paththrough the reservoir 5110 while in contact with the volume of watertherein.

According to one form, the reservoir 5110 may be removable from thehumidifier 5000, for example in a lateral direction as shown in FIG. 5Aand FIG. 5B.

The reservoir 5110 may also be configured to discourage egress of liquidtherefrom, such as when the reservoir 5110 is displaced and/or rotatedfrom its normal, working orientation, such as through any aperturesand/or in between its sub-components. As the flow of air to behumidified by the humidifier 5000 is typically pressurised, thereservoir 5110 may also be configured to prevent losses in pneumaticpressure through leak and/or flow impedance.

5.6.2.2 Conductive Portion

According to one arrangement, the reservoir 5110 comprises a conductiveportion 5120 configured to allow efficient transfer of heat from theheating element 5240 to the volume of liquid in the reservoir 5110. Inone form, the conductive portion 5120 may be arranged as a plate,although other shapes may also be suitable. All or a part of theconductive portion 5120 may be made of a thermally conductive materialsuch as aluminium (e.g. approximately 2 mm thick, such as 1 mm, 1.5 mm,2.5 mm or 3 mm), another heat conducting metal or some plastics. In somecases, suitable heat conductivity may be achieved with less conductivematerials of suitable geometry.

5.6.2.3 Humidifier Reservoir Dock

In one form, the humidifier 5000 may comprise a humidifier reservoirdock 5130 (as shown in FIG. 5B) configured to receive the humidifierreservoir 5110. In some arrangements, the humidifier reservoir dock 5130may comprise a locking feature such as a locking lever 5135 configuredto retain the reservoir 5110 in the humidifier reservoir dock 5130.

5.6.2.4 Water Level Indicator

The humidifier reservoir 5110 may comprise a water level indicator 5150as shown in FIG. 5A-5B. In some forms, the water level indicator 5150may provide one or more indications to a user such as the patient 1000or a care giver regarding a quantity of the volume of water in thehumidifier reservoir 5110. The one or more indications provided by thewater level indicator 5150 may include an indication of a maximum,predetermined volume of water, any portions thereof, such as 25%, 50% or75% or volumes such as 200 ml, 300 ml or 400 ml.

5.6.2.5 Humidifier Transducer(s)

The humidifier 5000 may comprise one or more humidifier transducers(sensors) 5210 instead of, or in addition to, transducers 4270 describedabove. Humidifier transducers 5210 may include one or more of an airpressure sensor 5212, an air flow rate transducer 5214, a temperaturesensor 5216, or a humidity sensor 5218 as shown in FIG. 5C. A humidifiertransducer 5210 may produce one or more output signals which may becommunicated to a controller such as the central controller 4230 and/orthe humidifier controller 5250. In some forms, a humidifier transducermay be located externally to the humidifier 5000 (such as in the aircircuit 4170) while communicating the output signal to the controller.

5.6.2.5.1 Pressure Transducer

One or more pressure transducers 5212 may be provided to the humidifier5000 in addition to, or instead of, a pressure sensor 4272 provided inthe RPT device 4000.

5.6.2.5.2 Flow Rate Transducer

One or more flow rate transducers 5214 may be provided to the humidifier5000 in addition to, or instead of, a flow rate sensor 4274 provided inthe RPT device 4000.

5.6.2.5.3 Temperature Transducer

The humidifier 5000 may comprise one or more temperature transducers5216. The one or more temperature transducers 5216 may be configured tomeasure one or more temperatures such as of the heating element 5240and/or of the flow of air downstream of the humidifier outlet 5004. Insome forms, the humidifier 5000 may further comprise a temperaturesensor 5216 to detect the temperature of the ambient air.

5.6.2.5.4 Humidity Transducer

In one form, the humidifier 5000 may comprise one or more humiditysensors 5218 to detect a humidity of a gas, such as the ambient air. Thehumidity sensor 5218 may be placed towards the humidifier outlet 5004 insome forms to measure a humidity of the gas delivered from thehumidifier 5000. The humidity sensor may be an absolute humidity sensoror a relative humidity sensor.

5.6.2.6 Heating Element

A heating element 5240 may be provided to the humidifier 5000 in somecases to provide a heat input to one or more of the volume of water inthe humidifier reservoir 5110 and/or to the flow of air. The heatingelement 5240 may comprise a heat generating component such as anelectrically resistive heating track. One suitable example of a heatingelement 5240 is a layered heating element such as one described in thePCT Patent Application Publication No. WO 2012/171072, which isincorporated herewith by reference in its entirety.

In some forms, the heating element 5240 may be provided in thehumidifier base 5006 where heat may be provided to the humidifierreservoir 5110 primarily by conduction as shown in FIG. 5B.

5.6.2.7 Humidifier Controller

According to one arrangement of the present technology, a humidifier5000 may comprise a humidifier controller 5250 as shown in FIG. 5C. Inone form, the humidifier controller 5250 may be a part of the centralcontroller 4230. In another form, the humidifier controller 5250 may bea separate controller, which may be in communication with the centralcontroller 4230.

In one form, the humidifier controller 5250 may receive as inputsmeasures of properties (such as temperature, humidity, pressure and/orflow rate), for example of the flow of air, the water in the reservoir5110 and/or the humidifier 5000. The humidifier controller 5250 may alsobe configured to execute or implement humidifier algorithms and/ordeliver one or more output signals.

As shown in FIG. 5C, the humidifier controller 5250 may comprise one ormore controllers, such as a central humidifier controller 5251, a heatedair circuit controller 5254 configured to control the temperature of aheated air circuit 4170 and/or a heating element controller 5252configured to control the temperature of a heating element 5240.

5.7 Breathing Waveforms

FIG. 6A shows a model typical breath waveform of a person whilesleeping. The horizontal axis is time, and the vertical axis isrespiratory flow rate. While the parameter values may vary, a typicalbreath may have the following approximate values: tidal volume Vt 0.5 L,inhalation time Ti 1.6 s, peak inspiratory flow rate Qpeak 0.4 L/s,exhalation time Te 2.4 s, peak expiratory flow rate Qpeak—0.5 L/s. Thetotal duration of the breath, Ttot, is about 4 s. The person typicallybreathes at a rate of about 15 breaths per minute (BPM), withVentilation Vent about 7.5 L/min. A typical duty cycle, the ratio of Tito Ttot, is about 40%.

5.8 Glossary

For the purposes of the present technology disclosure, in certain formsof the present technology, one or more of the following definitions mayapply. In other forms of the present technology, alternative definitionsmay apply.

5.8.1 General

Air: In certain forms of the present technology, air may be taken tomean atmospheric air, and in other forms of the present technology airmay be taken to mean some other combination of breathable gases, e.g.atmospheric air enriched with oxygen.

Ambient: In certain forms of the present technology, the term ambientwill be taken to mean (i) external of the treatment system or patient,and (ii) immediately surrounding the treatment system or patient.

For example, ambient humidity with respect to a humidifier may be thehumidity of air immediately surrounding the humidifier, e.g. thehumidity in the room where a patient is sleeping. Such ambient humiditymay be different to the humidity outside the room where a patient issleeping.

In another example, ambient pressure may be the pressure immediatelysurrounding or external to the body.

In certain forms, ambient (e.g., acoustic) noise may be considered to bethe background noise level in the room where a patient is located, otherthan for example, noise generated by an RPT device or emanating from amask or patient interface. Ambient noise may be generated by sourcesoutside the room.

Automatic Positive Airway Pressure (APAP) therapy: CPAP therapy in whichthe treatment pressure is automatically adjustable, e.g. from breath tobreath, between minimum and maximum limits, depending on the presence orabsence of indications of SDB events.

Continuous Positive Airway Pressure (CPAP) therapy: Respiratory pressuretherapy in which the treatment pressure is approximately constantthrough a respiratory cycle of a patient. In some forms, the pressure atthe entrance to the airways will be slightly higher during exhalation,and slightly lower during inhalation. In some forms, the pressure willvary between different respiratory cycles of the patient, for example,being increased in response to detection of indications of partial upperairway obstruction, and decreased in the absence of indications ofpartial upper airway obstruction.

Flow rate: The volume (or mass) of air delivered per unit time. Flowrate may refer to an instantaneous quantity. In some cases, a referenceto flow rate will be a reference to a scalar quantity, namely a quantityhaving magnitude only. In other cases, a reference to flow rate will bea reference to a vector quantity, namely a quantity having bothmagnitude and direction. Flow rate may be given the symbol Q. ‘Flowrate’ is sometimes shortened to simply ‘flow’ or ‘airflow’.

In the example of patient respiration, a flow rate may be nominallypositive for the inspiratory portion of a breathing cycle of a patient,and hence negative for the expiratory portion of the breathing cycle ofa patient. Total flow rate, Qt, is the flow rate of air leaving the RPTdevice. Vent flow rate, Qv, is the flow rate of air leaving a vent toallow washout of exhaled gases. Leak flow rate, Ql, is the flow rate ofleak from a patient interface system or elsewhere. Respiratory flowrate, Qr, is the flow rate of air that is received into the patient'srespiratory system.

Humidifier: The word humidifier will be taken to mean a humidifyingapparatus constructed and arranged, or configured with a physicalstructure to be capable of providing a therapeutically beneficial amountof water (H₂O) vapour to a flow of air to ameliorate a medicalrespiratory condition of a patient.

Leak: The word leak will be taken to be an unintended flow of air. Inone example, leak may occur as the result of an incomplete seal betweena mask and a patient's face. In another example leak may occur in aswivel elbow to the ambient.

Noise, conducted (acoustic): Conducted noise in the present documentrefers to noise which is carried to the patient by the pneumatic path,such as the air circuit and the patient interface as well as the airtherein. In one form, conducted noise may be quantified by measuringsound pressure levels at the end of an air circuit.

Noise, radiated (acoustic): Radiated noise in the present documentrefers to noise which is carried to the patient by the ambient air. Inone form, radiated noise may be quantified by measuring soundpower/pressure levels of the object in question according to ISO 3744.

Noise, vent (acoustic): Vent noise in the present document refers tonoise which is generated by the flow of air through any vents such asvent holes of the patient interface.

Patient: A person, whether or not they are suffering from a respiratorycondition.

Pressure: Force per unit area. Pressure may be expressed in a range ofunits, including cmH₂O, g-f/cm² and hectopascal. 1 cmH₂O is equal to 1g-f/cm² and is approximately 0.98 hectopascal. In this specification,unless otherwise stated, pressure is given in units of cmH₂O.

The pressure in the patient interface is given the symbol Pm, while thetreatment pressure, which represents a target value to be achieved bythe mask pressure Pm at the current instant of time, is given the symbolPt.

Respiratory Pressure Therapy (RPT): The application of a supply of airto an entrance to the airways at a treatment pressure that is typicallypositive with respect to atmosphere.

Ventilator: A mechanical device that provides pressure support to apatient to perform some or all of the work of breathing.

5.8.1.1 Materials

Silicone or Silicone Elastomer: A synthetic rubber. In thisspecification, a reference to silicone is a reference to liquid siliconerubber (LSR) or a compression moulded silicone rubber (CMSR). One formof commercially available LSR is SILASTIC (included in the range ofproducts sold under this trademark), manufactured by Dow Corning.Another manufacturer of LSR is Wacker. Unless otherwise specified to thecontrary, an exemplary form of LSR has a Shore A (or Type A) indentationhardness in the range of about 35 to about 45 as measured using ASTMD2240.

Polycarbonate: a thermoplastic polymer of Bisphenol-A Carbonate.

5.8.1.2 Mechanical Properties

Resilience: Ability of a material to absorb energy when deformedelastically and to release the energy upon unloading.

Resilient: Will release substantially all of the energy when unloaded.Includes e.g. certain silicones, and thermoplastic elastomers.

Hardness: The ability of a material per se to resist deformation (e.g.described by a Young's Modulus, or an indentation hardness scalemeasured on a standardised sample size).

-   -   ‘Soft’ materials may include silicone or thermo-plastic        elastomer (TPE), and may, e.g. readily deform under finger        pressure.    -   ‘Hard’ materials may include polycarbonate, polypropylene, steel        or aluminium, and may not e.g. readily deform under finger        pressure.

Stiffness (or rigidity) of a structure or component: The ability of thestructure or component to resist deformation in response to an appliedload. The load may be a force or a moment, e.g. compression, tension,bending or torsion. The structure or component may offer differentresistances in different directions.

Floppy structure or component: A structure or component that will changeshape, e.g. bend, when caused to support its own weight, within arelatively short period of time such as 1 second.

Rigid structure or component: A structure or component that will notsubstantially change shape when subject to the loads typicallyencountered in use. An example of such a use may be setting up andmaintaining a patient interface in sealing relationship with an entranceto a patient's airways, e.g. at a load of approximately 20 to 30 cmH₂Opressure.

As an example, an I-beam may comprise a different bending stiffness(resistance to a bending load) in a first direction in comparison to asecond, orthogonal direction. In another example, a structure orcomponent may be floppy in a first direction and rigid in a seconddirection.

5.8.2 Respiratory Cycle

Apnea: According to some definitions, an apnea is said to have occurredwhen flow falls below a predetermined threshold for a duration, e.g. 10seconds. An obstructive apnea will be said to have occurred when,despite patient effort, some obstruction of the airway does not allowair to flow. A central apnea will be said to have occurred when an apneais detected that is due to a reduction in breathing effort, or theabsence of breathing effort, despite the airway being patent. A mixedapnea occurs when a reduction or absence of breathing effort coincideswith an obstructed airway.

Breathing rate: The rate of spontaneous respiration of a patient,usually measured in breaths per minute.

Duty cycle: The ratio of inhalation time, Ti to total breath time, Ttot.

Effort (breathing): The work done by a spontaneously breathing personattempting to breathe.

Expiratory portion of a breathing cycle: The period from the start ofexpiratory flow to the start of inspiratory flow.

Flow limitation: Flow limitation will be taken to be the state ofaffairs in a patient's respiration where an increase in effort by thepatient does not give rise to a corresponding increase in flow. Whereflow limitation occurs during an inspiratory portion of the breathingcycle it may be described as inspiratory flow limitation. Where flowlimitation occurs during an expiratory portion of the breathing cycle itmay be described as expiratory flow limitation.

Types of flow limited inspiratory waveforms:

(i) Flattened: Having a rise followed by a relatively flat portion,followed by a fall.

(ii) M-shaped: Having two local peaks, one at the leading edge, and oneat the trailing edge, and a relatively flat portion between the twopeaks.

(iii) Chair-shaped: Having a single local peak, the peak being at theleading edge, followed by a relatively flat portion.

(iv) Reverse-chair shaped: Having a relatively flat portion followed bysingle local peak, the peak being at the trailing edge.

Hypopnea: According to some definitions, a hypopnea is taken to be areduction in flow, but not a cessation of flow. In one form, a hypopneamay be said to have occurred when there is a reduction in flow below athreshold rate for a duration. A central hypopnea will be said to haveoccurred when a hypopnea is detected that is due to a reduction inbreathing effort. In one form in adults, either of the following may beregarded as being hypopneas:

-   -   (i) a 30% reduction in patient breathing for at least 10 seconds        plus an associated 4% desaturation; or    -   (ii) a reduction in patient breathing (but less than 50%) for at        least 10 seconds, with an associated desaturation of at least 3%        or an arousal.

Hyperpnea: An increase in flow to a level higher than normal.

Inspiratory portion of a breathing cycle: The period from the start ofinspiratory flow to the start of expiratory flow will be taken to be theinspiratory portion of a breathing cycle.

Patency (airway): The degree of the airway being open, or the extent towhich the airway is open. A patent airway is open. Airway patency may bequantified, for example with a value of one (1) being patent, and avalue of zero (0), being closed (obstructed).

Positive End-Expiratory Pressure (PEEP): The pressure above atmospherein the lungs that exists at the end of expiration.

Peak flow rate (Qpeak): The maximum value of flow rate during theinspiratory portion of the respiratory flow waveform.

Respiratory flow rate, patient airflow rate, respiratory airflow rate(Qr): These terms may be understood to refer to the RPT device'sestimate of respiratory flow rate, as opposed to “true respiratory flowrate” or “true respiratory flow rate”, which is the actual respiratoryflow rate experienced by the patient, usually expressed in litres perminute.

Tidal volume (Vt): The volume of air inhaled or exhaled during normalbreathing, when extra effort is not applied. In principle theinspiratory volume Vi (the volume of air inhaled) is equal to theexpiratory volume Ve (the volume of air exhaled), and therefore a singletidal volume Vt may be defined as equal to either quantity. In practicethe tidal volume Vt is estimated as some combination, e.g. the mean, ofthe inspiratory volume Vi and the expiratory volume Ve.

(inhalation) Time (Ti): The duration of the inspiratory portion of therespiratory flow rate waveform.

(exhalation) Time (Te): The duration of the expiratory portion of therespiratory flow rate waveform.

(total) Time (Ttot): The total duration between the start of oneinspiratory portion of a respiratory flow rate waveform and the start ofthe following inspiratory portion of the respiratory flow rate waveform.

Typical recent ventilation: The value of ventilation around which recentvalues of ventilation Vent over some predetermined timescale tend tocluster, that is, a measure of the central tendency of the recent valuesof ventilation.

Upper airway obstruction (UAO): includes both partial and total upperairway obstruction. This may be associated with a state of flowlimitation, in which the flow rate increases only slightly or may evendecrease as the pressure difference across the upper airway increases(Starling resistor behaviour).

Ventilation (Vent): A measure of a rate of gas being exchanged by thepatient's respiratory system. Measures of ventilation may include one orboth of inspiratory and expiratory flow, per unit time. When expressedas a volume per minute, this quantity is often referred to as “minuteventilation”. Minute ventilation is sometimes given simply as a volume,understood to be the volume per minute.

5.8.3 Ventilation

Adaptive Servo-Ventilator (ASV): A servo-ventilator that has achangeable, rather than fixed target ventilation. The changeable targetventilation may be learned from some characteristic of the patient, forexample, a respiratory characteristic of the patient.

Backup rate: A parameter of a ventilator that establishes the minimumbreathing rate (typically in number of breaths per minute) that theventilator will deliver to the patient, if not triggered by spontaneousrespiratory effort.

Cycled: The termination of a ventilator's inspiratory phase. When aventilator delivers a breath to a spontaneously breathing patient, atthe end of the inspiratory portion of the breathing cycle, theventilator is said to be cycled to stop delivering the breath.

Expiratory positive airway pressure (EPAP): a base pressure, to which apressure varying within the breath is added to produce the desired maskpressure which the ventilator will attempt to achieve at a given time.

End expiratory pressure (EEP): Desired mask pressure which theventilator will attempt to achieve at the end of the expiratory portionof the breath. If the pressure waveform template □(□) is zero-valued atthe end of expiration, i.e. □(□)=0 when □=1, the EEP is equal to theEPAP.

Inspiratory positive airway pressure (IPAP): Maximum desired maskpressure which the ventilator will attempt to achieve during theinspiratory portion of the breath.

Pressure support: A number that is indicative of the increase inpressure during ventilator inspiration over that during ventilatorexpiration, and generally means the difference in pressure between themaximum value during inspiration and the base pressure (e.g.,PS=IPAP−EPAP). In some contexts pressure support means the differencewhich the ventilator aims to achieve, rather than what it actuallyachieves.

Servo-ventilator: A ventilator that measures patient ventilation, has atarget ventilation, and which adjusts the level of pressure support tobring the patient ventilation towards the target ventilation.

Spontaneous/Timed (S/T): A mode of a ventilator or other device thatattempts to detect the initiation of a breath of a spontaneouslybreathing patient. If however, the device is unable to detect a breathwithin a predetermined period of time, the device will automaticallyinitiate delivery of the breath.

Swing: Equivalent term to pressure support.

Triggered: When a ventilator delivers a breath of air to a spontaneouslybreathing patient, it is said to be triggered to do so at the initiationof the respiratory portion of the breathing cycle by the patient'sefforts.

5.8.4 Anatomy

5.8.4.1 Anatomy of the Face

Ala: the external outer wall or “wing” of each nostril (plural: alar)

Alare: The most lateral point on the nasal ala.

Alar curvature (or alar crest) point: The most posterior point in thecurved base line of each ala, found in the crease formed by the union ofthe ala with the cheek.

Auricle: The whole external visible part of the ear.

(nose) Bony framework: The bony framework of the nose comprises thenasal bones, the frontal process of the maxillae and the nasal part ofthe frontal bone.

(nose) Cartilaginous framework: The cartilaginous framework of the nosecomprises the septal, lateral, major and minor cartilages.

Columella: the strip of skin that separates the nares and which runsfrom the pronasale to the upper lip.

Columella angle: The angle between the line drawn through the midpointof the nostril aperture and a line drawn perpendicular to the Frankforthorizontal while intersecting subnasale.

Frankfort horizontal plane: A line extending from the most inferiorpoint of the orbital margin to the left tragion. The tragion is thedeepest point in the notch superior to the tragus of the auricle.

Glabella: Located on the soft tissue, the most prominent point in themidsagittal plane of the forehead.

Lateral nasal cartilage: A generally triangular plate of cartilage. Itssuperior margin is attached to the nasal bone and frontal process of themaxilla, and its inferior margin is connected to the greater alarcartilage.

Greater alar cartilage: A plate of cartilage lying below the lateralnasal cartilage. It is curved around the anterior part of the naris. Itsposterior end is connected to the frontal process of the maxilla by atough fibrous membrane containing three or four minor cartilages of theala.

Nares (Nostrils): Approximately ellipsoidal apertures forming theentrance to the nasal cavity. The singular form of nares is naris(nostril). The nares are separated by the nasal septum.

Naso-labial sulcus or Naso-labial fold: The skin fold or groove thatruns from each side of the nose to the corners of the mouth, separatingthe cheeks from the upper lip.

Naso-labial angle: The angle between the columella and the upper lip,while intersecting subnasale.

Otobasion inferior: The lowest point of attachment of the auricle to theskin of the face.

Otobasion superior: The highest point of attachment of the auricle tothe skin of the face.

Pronasale: the most protruded point or tip of the nose, which can beidentified in lateral view of the rest of the portion of the head.

Philtrum: the midline groove that runs from lower border of the nasalseptum to the top of the lip in the upper lip region.

Pogonion: Located on the soft tissue, the most anterior midpoint of thechin.

Ridge (nasal): The nasal ridge is the midline prominence of the nose,extending from the Sellion to the Pronasale.

Sagittal plane: A vertical plane that passes from anterior (front) toposterior (rear). The midsagittal plane is a sagittal plane that dividesthe body into right and left halves.

Sellion: Located on the soft tissue, the most concave point overlyingthe area of the frontonasal suture.

Septal cartilage (nasal): The nasal septal cartilage forms part of theseptum and divides the front part of the nasal cavity.

Subalare: The point at the lower margin of the alar base, where the alarbase joins with the skin of the superior (upper) lip.

Subnasal point: Located on the soft tissue, the point at which thecolumella merges with the upper lip in the midsagittal plane.

Supramenton: The point of greatest concavity in the midline of the lowerlip between labrale inferius and soft tissue pogonion

5.8.4.2 Anatomy of the Skull

Frontal bone: The frontal bone includes a large vertical portion, thesquama frontalis, corresponding to the region known as the forehead.

Mandible: The mandible forms the lower jaw. The mental protuberance isthe bony protuberance of the jaw that forms the chin.

Maxilla: The maxilla forms the upper jaw and is located above themandible and below the orbits. The frontal process of the maxillaprojects upwards by the side of the nose, and forms part of its lateralboundary.

Nasal bones: The nasal bones are two small oblong bones, varying in sizeand form in different individuals; they are placed side by side at themiddle and upper part of the face, and form, by their junction, the“bridge” of the nose.

Nasion: The intersection of the frontal bone and the two nasal bones, adepressed area directly between the eyes and superior to the bridge ofthe nose.

Occipital bone: The occipital bone is situated at the back and lowerpart of the cranium. It includes an oval aperture, the foramen magnum,through which the cranial cavity communicates with the vertebral canal.The curved plate behind the foramen magnum is the squama occipitalis.

Orbit: The bony cavity in the skull to contain the eyeball.

Parietal bones: The parietal bones are the bones that, when joinedtogether, form the roof and sides of the cranium.

Temporal bones: The temporal bones are situated on the bases and sidesof the skull, and support that part of the face known as the temple.

Zygomatic bones: The face includes two zygomatic bones, located in theupper and lateral parts of the face and forming the prominence of thecheek.

5.8.4.3 Anatomy of the Respiratory System

Diaphragm: A sheet of muscle that extends across the bottom of the ribcage. The diaphragm separates the thoracic cavity, containing the heart,lungs and ribs, from the abdominal cavity. As the diaphragm contractsthe volume of the thoracic cavity increases and air is drawn into thelungs.

Larynx: The larynx, or voice box houses the vocal folds and connects theinferior part of the pharynx (hypopharynx) with the trachea.

Lungs: The organs of respiration in humans. The conducting zone of thelungs contains the trachea, the bronchi, the bronchioles, and theterminal bronchioles. The respiratory zone contains the respiratorybronchioles, the alveolar ducts, and the alveoli.

Nasal cavity: The nasal cavity (or nasal fossa) is a large air filledspace above and behind the nose in the middle of the face. The nasalcavity is divided in two by a vertical fin called the nasal septum. Onthe sides of the nasal cavity are three horizontal outgrowths callednasal conchae (singular “concha”) or turbinates. To the front of thenasal cavity is the nose, while the back blends, via the choanae, intothe nasopharynx.

Pharynx: The part of the throat situated immediately inferior to (below)the nasal cavity, and superior to the oesophagus and larynx. The pharynxis conventionally divided into three sections: the nasopharynx(epipharynx) (the nasal part of the pharynx), the oropharynx(mesopharynx) (the oral part of the pharynx), and the laryngopharynx(hypopharynx).

5.8.5 Patient Interface

Anti-asphyxia valve (AAV): The component or sub-assembly of a masksystem that, by opening to atmosphere in a failsafe manner, reduces therisk of excessive CO₂ rebreathing by a patient.

Elbow: An elbow is an example of a structure that directs an axis offlow of air travelling therethrough to change direction through anangle. In one form, the angle may be approximately 90 degrees. Inanother form, the angle may be more, or less than 90 degrees. The elbowmay have an approximately circular cross-section. In another form theelbow may have an oval or a rectangular cross-section. In certain formsan elbow may be rotatable with respect to a mating component, e.g. about360 degrees. In certain forms an elbow may be removable from a matingcomponent, e.g. via a snap connection. In certain forms, an elbow may beassembled to a mating component via a one-time snap during manufacture,but not removable by a patient.

Frame: Frame will be taken to mean a mask structure that bears the loadof tension between two or more points of connection with a headgear. Amask frame may be a non-airtight load bearing structure in the mask.However, some forms of mask frame may also be air-tight.

Headgear: Headgear will be taken to mean a form of positioning andstabilizing structure designed for use on a head. For example theheadgear may comprise a collection of one or more struts, ties andstiffeners configured to locate and retain a patient interface inposition on a patient's face for delivery of respiratory therapy. Someties are formed of a soft, flexible, elastic material such as alaminated composite of foam and fabric.

Membrane: Membrane will be taken to mean a typically thin element thathas, preferably, substantially no resistance to bending, but hasresistance to being stretched.

Plenum chamber: a mask plenum chamber will be taken to mean a portion ofa patient interface having walls at least partially enclosing a volumeof space, the volume having air therein pressurised above atmosphericpressure in use. A shell may form part of the walls of a mask plenumchamber.

Seal: May be a noun form (“a seal”) which refers to a structure, or averb form (“to seal”) which refers to the effect. Two elements may beconstructed and/or arranged to ‘seal’ or to effect ‘sealing’therebetween without requiring a separate ‘seal’ element per se.

Shell: A shell will be taken to mean a curved, relatively thin structurehaving bending, tensile and compressive stiffness. For example, a curvedstructural wall of a mask may be a shell. In some forms, a shell may befaceted. In some forms a shell may be airtight. In some forms a shellmay not be airtight.

Stiffener: A stiffener will be taken to mean a structural componentdesigned to increase the bending resistance of another component in atleast one direction.

Strut: A strut will be taken to be a structural component designed toincrease the compression resistance of another component in at least onedirection.

Swivel (noun): A subassembly of components configured to rotate about acommon axis, preferably independently, preferably under low torque. Inone form, the swivel may be constructed to rotate through an angle of atleast 360 degrees. In another form, the swivel may be constructed torotate through an angle less than 360 degrees. When used in the contextof an air delivery conduit, the sub-assembly of components preferablycomprises a matched pair of cylindrical conduits. There may be little orno leak flow of air from the swivel in use.

Tie (noun): A structure designed to resist tension.

Vent: (noun): A structure that allows a flow of air from an interior ofthe mask, or conduit, to ambient air for clinically effective washout ofexhaled gases. For example, a clinically effective washout may involve aflow rate of about 10 litres per minute to about 100 litres per minute,depending on the mask design and treatment pressure.

5.8.6 Shape of Structures

Products in accordance with the present technology may comprise one ormore three-dimensional mechanical structures, for example a mask cushionor an impeller. The three-dimensional structures may be bounded bytwo-dimensional surfaces. These surfaces may be distinguished using alabel to describe an associated surface orientation, location, function,or some other characteristic. For example a structure may comprise oneor more of an anterior surface, a posterior surface, an interior surfaceand an exterior surface. In another example, a seal-forming structuremay comprise a face-contacting (e.g. outer) surface, and a separatenon-face-contacting (e.g. underside or inner) surface. In anotherexample, a structure may comprise a first surface and a second surface.

To facilitate describing the shape of the three-dimensional structuresand the surfaces, we first consider a cross-section through a surface ofthe structure at a point, p. See FIG. 3B to FIG. 3F, which illustrateexamples of cross-sections at point p on a surface, and the resultingplane curves. FIGS. 3B to 3F also illustrate an outward normal vector atp. The outward normal vector at p points away from the surface. In someexamples we describe the surface from the point of view of an imaginarysmall person standing upright on the surface.

5.8.6.1 Curvature in One Dimension

The curvature of a plane curve at p may be described as having a sign(e.g. positive, negative) and a magnitude (e.g. 1/radius of a circlethat just touches the curve at p).

Positive curvature: If the curve at p turns towards the outward normal,the curvature at that point will be taken to be positive (if theimaginary small person leaves the point p they must walk uphill). SeeFIG. 3B (relatively large positive curvature compared to FIG. 3C) andFIG. 3C (relatively small positive curvature compared to FIG. 3B). Suchcurves are often referred to as concave.

Zero curvature: If the curve at p is a straight line, the curvature willbe taken to be zero (if the imaginary small person leaves the point p,they can walk on a level, neither up nor down). See FIG. 3D.

Negative curvature: If the curve at p turns away from the outwardnormal, the curvature in that direction at that point will be taken tobe negative (if the imaginary small person leaves the point p they mustwalk downhill). See FIG. 3E (relatively small negative curvaturecompared to FIG. 3F) and FIG. 3F (relatively large negative curvaturecompared to FIG. 3E). Such curves are often referred to as convex.

5.8.6.2 Curvature of Two Dimensional Surfaces

A description of the shape at a given point on a two-dimensional surfacein accordance with the present technology may include multiple normalcross-sections. The multiple cross-sections may cut the surface in aplane that includes the outward normal (a “normal plane”), and eachcross-section may be taken in a different direction. Each cross-sectionresults in a plane curve with a corresponding curvature. The differentcurvatures at that point may have the same sign, or a different sign.Each of the curvatures at that point has a magnitude, e.g. relativelysmall. The plane curves in FIGS. 3B to 3F could be examples of suchmultiple cross-sections at a particular point.

Principal curvatures and directions: The directions of the normal planeswhere the curvature of the curve takes its maximum and minimum valuesare called the principal directions. In the examples of FIG. 3B to FIG.3F, the maximum curvature occurs in FIG. 3B, and the minimum occurs inFIG. 3F, hence FIG. 3B and FIG. 3F are cross sections in the principaldirections. The principal curvatures at p are the curvatures in theprincipal directions.

Region of a surface: A connected set of points on a surface. The set ofpoints in a region may have similar characteristics, e.g. curvatures orsigns.

Saddle region: A region where at each point, the principal curvatureshave opposite signs, that is, one is positive, and the other is negative(depending on the direction to which the imaginary person turns, theymay walk uphill or downhill).

Dome region: A region where at each point the principal curvatures havethe same sign, e.g. both positive (a “concave dome”) or both negative (a“convex dome”).

Cylindrical region: A region where one principal curvature is zero (or,for example, zero within manufacturing tolerances) and the otherprincipal curvature is non-zero.

Planar region: A region of a surface where both of the principalcurvatures are zero (or, for example, zero within manufacturingtolerances).

Edge of a surface: A boundary or limit of a surface or region.

Path: In certain forms of the present technology, ‘path’ will be takento mean a path in the mathematical—topological sense, e.g. a continuousspace curve from f(0) to f(1) on a surface. In certain forms of thepresent technology, a ‘path’ may be described as a route or course,including e.g. a set of points on a surface. (The path for the imaginaryperson is where they walk on the surface, and is analogous to a gardenpath).

Path length: In certain forms of the present technology, ‘path length’will be taken to mean the distance along the surface from f(0) to f(1),that is, the distance along the path on the surface. There may be morethan one path between two points on a surface and such paths may havedifferent path lengths. (The path length for the imaginary person wouldbe the distance they have to walk on the surface along the path).

Straight-line distance: The straight-line distance is the distancebetween two points on a surface, but without regard to the surface. Onplanar regions, there would be a path on the surface having the samepath length as the straight-line distance between two points on thesurface. On non-planar surfaces, there may be no paths having the samepath length as the straight-line distance between two points. (For theimaginary person, the straight-line distance would correspond to thedistance ‘as the crow flies’.)

5.8.6.3 Space Curves

Space curves: Unlike a plane curve, a space curve does not necessarilylie in any particular plane. A space curve may be closed, that is,having no endpoints. A space curve may be considered to be aone-dimensional piece of three-dimensional space. An imaginary personwalking on a strand of the DNA helix walks along a space curve. Atypical human left ear comprises a helix, which is a left-hand helix,see FIG. 3Q. A typical human right ear comprises a helix, which is aright-hand helix, see FIG. 3R. FIG. 3S shows a right-hand helix. Theedge of a structure, e.g. the edge of a membrane or impeller, may followa space curve. In general, a space curve may be described by a curvatureand a torsion at each point on the space curve. Torsion is a measure ofhow the curve turns out of a plane. Torsion has a sign and a magnitude.The torsion at a point on a space curve may be characterised withreference to the tangent, normal and binormal vectors at that point.

Tangent unit vector (or unit tangent vector): For each point on a curve,a vector at the point specifies a direction from that point, as well asa magnitude. A tangent unit vector is a unit vector pointing in the samedirection as the curve at that point. If an imaginary person were flyingalong the curve and fell off her vehicle at a particular point, thedirection of the tangent vector is the direction she would betravelling.

Unit normal vector: As the imaginary person moves along the curve, thistangent vector itself changes. The unit vector pointing in the samedirection that the tangent vector is changing is called the unitprincipal normal vector. It is perpendicular to the tangent vector.

Binormal unit vector: The binormal unit vector is perpendicular to boththe tangent vector and the principal normal vector. Its direction may bedetermined by a right-hand rule (see e.g. FIG. 3P), or alternatively bya left-hand rule (FIG. 3O).

Osculating plane: The plane containing the unit tangent vector and theunit principal normal vector. See FIGS. 3O and 3P.

Torsion of a space curve: The torsion at a point of a space curve is themagnitude of the rate of change of the binormal unit vector at thatpoint. It measures how much the curve deviates from the osculatingplane. A space curve which lies in a plane has zero torsion. A spacecurve which deviates a relatively small amount from the osculating planewill have a relatively small magnitude of torsion (e.g. a gently slopinghelical path). A space curve which deviates a relatively large amountfrom the osculating plane will have a relatively large magnitude oftorsion (e.g. a steeply sloping helical path). With reference to FIG.3S, since T2>T1, the magnitude of the torsion near the top coils of thehelix of FIG. 3S is greater than the magnitude of the torsion of thebottom coils of the helix of FIG. 3S

With reference to the right-hand rule of FIG. 3P, a space curve turningtowards the direction of the right-hand binormal may be considered ashaving a right-hand positive torsion (e.g. a right-hand helix as shownin FIG. 3S). A space curve turning away from the direction of theright-hand binormal may be considered as having a right-hand negativetorsion (e.g. a left-hand helix).

Equivalently, and with reference to a left-hand rule (see FIG. 3O), aspace curve turning towards the direction of the left-hand binormal maybe considered as having a left-hand positive torsion (e.g. a left-handhelix). Hence left-hand positive is equivalent to right-hand negative.See FIG. 3T.

5.8.6.4 Holes

A surface may have a one-dimensional hole, e.g. a hole bounded by aplane curve or by a space curve. Thin structures (e.g. a membrane) witha hole, may be described as having a one-dimensional hole. See forexample the one dimensional hole in the surface of structure shown inFIG. 3I, bounded by a plane curve.

A structure may have a two-dimensional hole, e.g. a hole bounded by asurface. For example, an inflatable tyre has a two dimensional holebounded by the interior surface of the tyre. In another example, abladder with a cavity for air or gel could have a two-dimensional hole.See for example the cushion of FIG. 3L and the example cross-sectionstherethrough in FIG. 3M and FIG. 3N, with the interior surface boundinga two dimensional hole indicated. In a yet another example, a conduitmay comprise a one-dimension hole (e.g. at its entrance or at its exit),and a two-dimension hole bounded by the inside surface of the conduit.See also the two dimensional hole through the structure shown in FIG.3K, bounded by a surface as shown.

5.9 Other Remarks

Unless the context clearly dictates otherwise and where a range ofvalues is provided, it is understood that each intervening value, to thetenth of the unit of the lower limit, between the upper and lower limitof that range, and any other stated or intervening value in that statedrange is encompassed within the technology. The upper and lower limitsof these intervening ranges, which may be independently included in theintervening ranges, are also encompassed within the technology, subjectto any specifically excluded limit in the stated range. Where the statedrange includes one or both of the limits, ranges excluding either orboth of those included limits are also included in the technology.

Furthermore, where a value or values are stated herein as beingimplemented as part of the technology, it is understood that such valuesmay be approximated, unless otherwise stated, and such values may beutilized to any suitable significant digit to the extent that apractical technical implementation may permit or require it.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this technology belongs. Although any methods andmaterials similar or equivalent to those described herein can also beused in the practice or testing of the present technology, a limitednumber of the exemplary methods and materials are described herein.

When a particular material is identified as being used to construct acomponent, obvious alternative materials with similar properties may beused as a substitute. Furthermore, unless specified to the contrary, anyand all components herein described are understood to be capable ofbeing manufactured and, as such, may be manufactured together orseparately.

It must be noted that as used herein and in the appended claims, thesingular forms “a”, “an”, and “the” include their plural equivalents,unless the context clearly dictates otherwise.

All publications mentioned herein are incorporated herein by referencein their entirety to disclose and describe the methods and/or materialswhich are the subject of those publications. The publications discussedherein are provided solely for their disclosure prior to the filing dateof the present application. Nothing herein is to be construed as anadmission that the present technology is not entitled to antedate suchpublication by virtue of prior invention. Further, the dates ofpublication provided may be different from the actual publication dates,which may need to be independently confirmed.

The terms “comprises” and “comprising” should be interpreted asreferring to elements, components, or steps in a non-exclusive manner,indicating that the referenced elements, components, or steps may bepresent, or utilized, or combined with other elements, components, orsteps that are not expressly referenced.

The subject headings used in the detailed description are included onlyfor the ease of reference of the reader and should not be used to limitthe subject matter found throughout the disclosure or the claims. Thesubject headings should not be used in construing the scope of theclaims or the claim limitations.

Although the technology herein has been described with reference toparticular examples, it is to be understood that these examples aremerely illustrative of the principles and applications of thetechnology. In some instances, the terminology and symbols may implyspecific details that are not required to practice the technology. Forexample, although the terms “first” and “second” may be used, unlessotherwise specified, they are not intended to indicate any order but maybe utilised to distinguish between distinct elements. Furthermore,although process steps in the methodologies may be described orillustrated in an order, such an ordering is not required. Those skilledin the art will recognize that such ordering may be modified and/oraspects thereof may be conducted concurrently or even synchronously.

It is therefore to be understood that numerous modifications may be madeto the illustrative examples and that other arrangements may be devisedwithout departing from the spirit and scope of the technology.

5.10 REFERENCE SIGNS LIST patient 1000 bed partner 1100 patientinterface 3000 patient interface chamber 3001 sub-assembly 3002 seal -forming structure 3100 nasal portion 3101 oral portion 3102 nasalportion hole 3103 oral portion hole 3104 nasal portion hole divider 3105plenum chamber 3200 plenum chamber hole 3201 connection rim 3202 slot3203 detent 3204 chord 3210 superior point 3220 inferior point 3230positioning and stabilising structure 3300 clip 3301 superior tie 3302inferior tie 3303 posterior portion 3304 clip magnet 3305 crossbar 3306overhang 3307 vent 3400 plenum chamber vent hole 3401 connection port3600 forehead support 3700 conduit connector 3800 conduit connector end3802 conduit connector inlet hole 3803 conduit connector outlet hole3804 baffle 3805 conduit connector spacer 3806 conduit connectorattachment structure 3807 conduit connector outlet 3808 conduitconnector vent outlet 3830 conduit connector vent hole 3831 conduitconnector vent inlet 3832 conduit connector vent spacer 3833anti-asphyxia valve assembly 3850 anti-asphyxia valve flap 3851anti-asphyxia valve hole 3852 anti-asphyxia valve flap connector hole3853 anti-asphyxia valve flap connector 3854 anti-asphyxia valve holedivider 3855 anti-asphyxia valve flap hinge 3856 intermediate conduitconnector inlet seal 3860 conduit connector outlet seal 3861 diffusercover 3870 diffuser cavity 3871 inferior tie tab 3880 clip receiver 3881notch 3882 flexible portion 3883 tab connector 3884 flange 3885 recess3886 flange opening 3887 first tab 3890 second tab 3891 catch 3892 gap3893 conduit 3900 sleeve 3901 tie connector 3902 connection port housing3903 concertina section 3904 RPT device 4000 external housing 4010 upperportion 4012 lower portion 4014 panel 4015 chassis 4016 handle 4018pneumatic block 4020 air filter 4110 inlet air filter 4112 outlet airfilter 4114 muffler 4120 inlet muffler 4122 outlet muffler 4124 pressuregenerator 4140 blower 4142 motor 4144 anti - spill back valve 4160 aircircuit 4170 supplemental oxygen 4180 electrical components 4200 printedcircuit board assembly (PBCA) 4202 power supply 4210 input device 4220central controller 4230 clock 4232 therapy device controller 4240protection circuits 4250 memory 4260 transducer 4270 pressure sensor4272 flow rate sensor 4274 motor speed transducer 4276 datacommunication interface 4280 remote external communication network 4282local external communication network 4284 remote external device 4286local external device 4288 output device 4290 display driver 4292display 4294 humidifier 5000 humidifier inlet 5002 humidifier outlet5004 humidifier base 5006 humidifier reservoir 5110 reservoir 5110conductive portion 5120 humidifier reservoir dock 5130 locking lever5135 water level indicator 5150 humidifier transducer 5210 air pressuresensor 5212 air flow rate transducer 5214 temperature sensor 5216humidity sensor 5218 heating element 5240 humidifier controller 5250central humidifier controller 5251 heating element controller 5252 aircircuit controller 5254 elbow assembly 7700 elbow member 7710 vent hole7720 clip member 7730 pinch arm 7740 catch portion 7750 connectingportion 7760 button or trigger portion 7780 finger-grip portion 7781swivel connector 7790 ring member 7990

The invention claimed is:
 1. A patient interface comprising: a plenumchamber at least partly forming a patient interface chamber that ispressurisable to a therapeutic pressure of at least 6 cmH₂O aboveambient air pressure, the plenum chamber including a first plenumchamber hole and a second plenum chamber hole, the first plenum chamberhole and the second plenum chamber hole each being sized and structuredto receive a flow of air at the therapeutic pressure for breathing by apatient, a seal-forming structure constructed and arranged to form aseal with a region of the patient's face surrounding an entrance to thepatient's airways, said seal-forming structure having at least one holetherein such that the flow of air at the therapeutic pressure isdelivered to at least an entrance to the patient's nares, theseal-forming structure constructed and arranged to maintain thetherapeutic pressure in the patient interface chamber throughout thepatient's respiratory cycle in use; a first conduit and a second conduiteach being sized and structured to receive the flow of air at thetherapeutic pressure for breathing by the patient, the first conduit andthe second conduit being constructed from silicone; a first conduitconnector configured to pneumatically connect the first conduit to thefirst plenum chamber hole to provide the flow of air at the therapeuticpressure to the patient interface chamber for breathing by the patientand a second conduit connector configured to pneumatically connect thesecond conduit to the second plenum chamber hole to provide the flow ofair at the therapeutic pressure to the patient interface chamber forbreathing by the patient, the first conduit connector and the secondconduit connector being constructed from a relatively rigid, plasticmaterial; and a positioning and stabilising structure to provide a forceto hold the seal-forming structure in a therapeutically effectiveposition on the patient's head, the positioning and stabilisingstructure comprising: a pair of superior ties, each of the superior tiesbeing constructed and arranged so that at least a portion of thesuperior tie overlies a corresponding lateral region of the patient'shead superior to an otobasion superior of the patient's head in use; anda pair of inferior ties, each of the inferior ties being constructed andarranged so that at least a portion of the inferior tie overlies acorresponding lateral region of the patient's head inferior to anotobasion inferior of the patient's head in use, wherein an inferior tietab is connected to each of the first conduit connector and the secondconduit connector by a flange and is configured to be connected to acorresponding one of the inferior ties, wherein the first conduitconnector and the second conduit connector each includes ananti-asphyxia valve that is configured to allow the patient to breathfrom ambient through their mouth in the absence of a flow of pressurisedair through the first plenum chamber hole and the second plenum chamberhole, wherein each of the first conduit connector and the second conduitconnector further comprises a conduit connection end connected to acorresponding one of the first conduit and the second conduit, whereineach of the first conduit connector and the second conduit connectorfurther comprises a first tab and a second tab to releasably connect thefirst conduit connector and the second conduit connector to the plenumchamber at the first plenum chamber hole and the second plenum chamberhole, respectively, and wherein the first tab and the second tab areconfigured such that the first conduit connector and the second conduitconnector are only releasably connectable to the plenum chamber byengaging the first tab with the plenum chamber followed by engaging thesecond tab with the plenum chamber.
 2. The patient interface of claim 1,wherein the anti-asphyxia valve in each of the first conduit connectorand the second conduit connector includes an anti-asphyxia valve hole.3. The patient interface of claim 2, wherein each anti-asphyxia valvehole is shaped and dimensioned to allow the patient to breathetherethrough if the other anti-asphyxia valve hole is occluded.
 4. Thepatient interface of claim 3, wherein the anti-asphyxia valve in each ofthe first conduit connector and the second conduit connector furthercomprises an anti-asphyxia valve flap.
 5. The patient interface of claim4, wherein the anti-asphyxia valve flap of each of the first conduitconnector and the second conduit connector is configured to occlude theanti-asphyxia valve hole of a corresponding one of the first conduitconnector and the second conduit connector in a closed position suchthat the flow of air at the therapeutic pressure traveling through acorresponding one of the first conduit connector and the second conduitconnector is directed to the patient interface chamber and preventedfrom escaping to atmosphere via the anti-asphyxia valve hole during thepatient's entire respiratory cycle.
 6. The patient interface of claim 5,wherein, in an open position, the anti-asphyxia valve flap of each ofthe first conduit connector and the second conduit connector isconfigured to allow the patient to breath from ambient through theirmouth via the anti-asphyxia valve hole of a corresponding one of thefirst conduit connector and the second conduit connector in the absenceof a flow of pressurised air through the first plenum chamber hole andthe second plenum chamber hole.
 7. The patient interface of claim 6,wherein the anti-asphyxia valve hole of each of the first conduitconnector and the second conduit connector is divided by ananti-asphyxia valve hole divider that prevents the correspondinganti-asphyxia valve flap from passing through the anti-asphyxia valvehole.
 8. The patient interface of claim 1, wherein the anti-asphyxiavalve of each of the first conduit connector and the second conduitconnector is configured to operate independently of the other.
 9. Thepatient interface of claim 1, wherein the plenum chamber comprises aplurality of plenum chamber vent holes.
 10. The patient interface ofclaim 1, further comprising a seal between each of the first conduitconnector and the second conduit connector and a corresponding one ofthe first plenum chamber hole and the second plenum chamber hole. 11.The patient interface of claim 10, wherein the seal is formed on each ofthe first conduit connector and the second conduit connector, the sealbeing configured to engage the plenum chamber at a corresponding one ofthe first plenum chamber hole and the second plenum chamber hole. 12.The patient interface of claim 11, wherein the seal is permanentlyjoined to a corresponding one of the first conduit connector and thesecond conduit connector.
 13. The patient interface of claim 12, whereinthe seal is constructed of silicone.
 14. The patient interface of claim1, wherein each of the flanges further comprises a flange opening and arecess, wherein each of the inferior tie tabs further comprises a tabconnector configured to join each of the inferior tie tabs to acorresponding one of the flanges by passing through the correspondingflange opening and engaging the corresponding recess.
 15. The patientinterface of claim 14, further comprising a clip configured to beconnected to each of the inferior ties, wherein each of the inferior tietabs further comprises a clip receiver configured to be removablyconnected to a corresponding one of the clips to connect the inferiorties.
 16. The patient interface of claim 15, wherein each of the clipsand each of the clip receivers comprises a magnet oriented and chargedto facilitate a removable connection.
 17. The patient interface of claim16, wherein each of the clip receivers comprises a notch and each of theclips comprise a protrusion, each protrusion being configured to engagea corresponding notch to limit rotation of the clip relative to thecorresponding clip receiver.
 18. The patient interface of claim 1,wherein the first tab and the second tab are configured such that thefirst conduit connector and the second conduit connector are onlydisconnectable from the plenum chamber by disengaging the second tabfrom the plenum chamber followed by disengaging the first tab from theplenum chamber.
 19. The patient interface of claim 18, wherein theplenum chamber further comprises a slot proximal to each of the firstplenum chamber hole and the second plenum chamber hole, wherein thefirst tab of each of the first conduit connector and the second conduitconnector is configured to engage the slot associated with acorresponding one of the first plenum chamber hole and the second plenumchamber hole, and wherein each of the first conduit connector and thesecond conduit connector is rotatable about the corresponding slot whenthe first tab of each of the first conduit connector and the secondconduit connector is engaged with the corresponding slot.
 20. Thepatient interface of claim 19, wherein the plenum chamber furthercomprises a detent proximal to each of the first plenum chamber hole andthe second plenum chamber hole, and wherein the second tab of each ofthe first conduit connector and the second conduit connector furthercomprises a catch, the catch being configured to engage the detentassociated with a corresponding one of the first plenum chamber hole andthe second plenum chamber hole with a snap-fit.
 21. The patientinterface of claim 20, wherein the second tab of each of the firstconduit connector and the second conduit connector is flexible.
 22. Thepatient interface of claim 21, wherein each of the first conduitconnector and the second conduit connector further comprises a gap oneach side of the corresponding second tab such that the second tab iscantilevered from each of the first conduit connector and the secondconduit connector.
 23. The patient interface of claim 1, wherein theseal-forming structure further comprises a nasal portion configured toseal around the patient's nares and an oral portion configured to sealaround the patient's mouth.
 24. The patient interface of claim 1,further comprising: a connection port housing, each of the first conduitand the second conduit in pneumatic communication with the connectionport housing, and a connection port connected to the connection porthousing, the connection port configured to be connected to an aircircuit to receive the flow of air at the therapeutic pressure.
 25. Thepatient interface of claim 24, wherein the connection port furthercomprises an elbow.
 26. The patient interface of claim 25, wherein theconnection port further comprises at least one vent hole.
 27. Thepatient interface of claim 26, wherein the connection port is swivelablyconnected to the connection port housing.
 28. The patient interface ofclaim 27, wherein the connection port and the connection port housingare configured to be positioned superior to the patient's head in use.